Bell 407 FADEC System Troubleshooting Guide Page 1 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File AD12BitFlt 73-25-04-116 Hard Parent N/A Fault Description The ECU has detected a problem with an internal chip responsible for converting input sensor analog data to digital data Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 2 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File AD8BitFlt 73-25-04-116 Hard Parent N/A Fault Description The ECU has detected a problem with an internal chip responsible for converting input voltage and current data to digital data Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 3 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File AF28Flt 73-25-04-117 Soft Parent AF28Flt Fault Description The ECU has detected that its power input from the aircraft dc bus was not within limits for at least 30 seconds Fault Test Conditions Continuous Possible Fault Causes Low airframe battery, FADEC circuit breaker pulled with engine running, high voltage from ground power source Troubleshooting Prodedure See troubleshooting instructions for AF28RgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 4 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File AF28RgFlt 73-25-04-117 Soft Child AF28Flt Fault Description The ECU has detected that its power input from the aircraft dc bus was not within limits for at least 30 seconds Fault Test Conditions Continuous Possible Fault Causes Low airframe battery, FADEC circuit breaker pulled with engine running, high voltage from ground power source Fault Limits Special Limit Low High Open Circuit Reading 8.5 vdc 35 vdc N/A Troubleshooting Prodedure Compare AF28Raw parameter against range limits at power up with both battery and ground power source. Also monitor during engine start for low voltage. Bell 407 FADEC System Troubleshooting Guide Page 5 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File AL28Flt 73-25-04-111 Soft Parent AL28Flt Fault Description The ECU has detected that its power input provided by the engine PMA is not with limits for at least 4 seconds or the amount of ac ripple voltage produced by the alternator is too high Fault Test Conditions Test enabled at N2 > 85% Possible Fault Causes Bad engine PMA or one phase of the alternator is open or shorted Fault Limits Special Limit Low High Open Circuit Reading 8.5 vdc 60 vdc N/A ac ripple > 3 vac Troubleshooting Prodedure Compare Al28Raw parameter against range limits when the engine is running at 85% Nr. Also check that the Altripraw ac ripple is less that 3 vac. If voltage is low but ripple is normal, replace the PMA. If voltage is low but ripple is high, check for an open or short circuit between the engine PMA and ECU. Repair effected component as necessary. Bell 407 FADEC System Troubleshooting Guide Page 6 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File AMFlt 73-25-04-128 Manual Parent N/A Fault Description The ECU has detected a problem with either the HMU auto/manual solenoid circuitry or a problem with the FADEC auto/manual mode selection switch Fault Test Conditions Continuous Possible Fault Causes Bad FADEC auto/manual select switch or wiring to the HMU auto/manual solenoid Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for either the AMSolFlt or AMSwFlt child faults Bell 407 FADEC System Troubleshooting Guide Page 7 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File AMIFlt 73-25-04-103 Manual Child AMIFlt Fault Description The ECU has detected a problem with the current flow from the HMU auto/manual solenoid Fault Test Conditions Continuous Possible Fault Causes Open circuit between ECU and HMU auto/manual solenoid Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Auto/manual solenoid current outside 0.25 amp and 1.5 amp range when valve is energized, auto/manual solenoid current greater than 0.3 amp with manual mode selected Troubleshooting Prodedure Power up aircraft with the mode select switch in manual mode. While in manual mode, AMIBitRaw should be less than 0.3 amp. Select auto mode, AMIBitRaw should be between 0.25 amp and 1.5 amp. In either case, check wiring resistance of HMU auto/manual solenoid circuit. Bell 407 FADEC System Troubleshooting Guide Page 8 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File AMSolFlt 73-25-04-103 Manual Child AMSolFlt Fault Description The ECU has detected a problem with either the HMU auto/manual solenoid circuitry or a problem with the FADEC auto/manual mode selection switch Fault Test Conditions Continuous Possible Fault Causes High side short to ground from the ECU to the HMU stepper motor or auto/manual solenoid, any phase return from the HMU stepper motor to the ECU shorted to ground, or the HMU auto/manual solenoid return wire from the HMU to the ECU shorted to ground Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Auto/manual solenoid current outside 0.25 amp and 1.5 amp range when valve is energized, auto/manual solenoid current greater than 0.3 amp with manual mode selected, ECU auto/manual solenoid driver circuit senses that a ground exists on the solenoid return with manual selected, ECU auto/manual solenoid driver circuit senses that an open circuit exists on the solenoid return with auto selected Troubleshooting Prodedure If this fault occurs in the presence of a AMSwFlt, troubleshoot AMSwFlt fault first. Power up aircraft with the mode select switch in manual mode. While in manual mode, the parameters should be: ManSel = TRUE, AutoSel = FALSE, AMVbit = FALSE, AMIBit = FALSE, SWMONVbit = FALSE. If AMIbit = TRUE, Replace ECU. If AMVbit = TRUE, check for short on auto/manual solenoid return wiring from the HMU to the ECU. If no fault is present, select auto mode. If fault occurs, check for shorted circuits between the ECU and HMU stepper motor and auto/manual solenoid. Bell 407 FADEC System Troubleshooting Guide Page 9 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File AMSwFlt 73-25-04-119 Manual Child AMSwFlt Fault Description The ECU has detected a problem with the FADEC auto/manual mode selection switch Fault Test Conditions Continuous Possible Fault Causes Bad FADEC mode select switch or wiring from the switch to the ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Fault is declared if the ECU detects that neither mode is selected or if both modes are selected simultaneously Troubleshooting Prodedure Power up aircraft with the mode select switch in manual mode. While in manual mode, ManSel should be TRUE and AutoSel should be FALSE. Select Auto Mode. AutoSel should be TRUE and ManSel should be FALSE. A grounded input makes the input TRUE. An open input makes the input FALSE. The AutoSel and ManSel inputs should not both be TRUE or FALSE simultaneously. Troubleshoot switch and wiring as applicable. Bell 407 FADEC System Troubleshooting Guide Page 10 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File ARINCFltAn 73-25-04-127 Soft N/A N/A Fault Description This fault code not used in this application Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 11 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File ARINCHWFlt 73-25-04-116 Soft N/A N/A Fault Description This fault code not used in this application Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 12 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File BacCompFlt 73-25-04-116 Soft Parent N/A Fault Description The ECU has detected that it has not completed its background tasks within the allotted time period Fault Test Conditions Power up or during background tasks Possible Fault Causes Internal ECU Failure. Very unlikely to occur. Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 13 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File CJCFlt 73-25-04-116 Soft Parent CJCFlt Fault Description The ECU has detected a problem with its internal cold junction used to process its MGT input signal Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure. Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for either a CJCRgFlt or CJCRtFlt child fault Bell 407 FADEC System Troubleshooting Guide Page 14 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File CJCRgFlt 73-25-04-116 Soft Child CJCFlt Fault Description The ECU has detected a problem with its internal cold junction used to process its MGT input signal Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure. Fault Limits Special Limit Low High Open Circuit Reading -80°F 250°F N/A Troubleshooting Prodedure Record CJCRaw signal. Replace ECU and include value of CJCRaw signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 15 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File CJCRtFlt 73-25-04-116 Soft Child CJCFlt Fault Description The ECU has detected a problem with its internal cold junction used to process its MGT input signal Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure. Fault Limits Special Limit Low High Open Circuit Reading -80°F 250°F N/A Troubleshooting Prodedure Record CJCRaw signal. Replace ECU and include value of CJCRaw signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 16 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File CPAntFlt 73-25-04-113 Soft Parent CPFlt Fault Description The ECU has detected a problem with its collective pitch input used to maintain rotor rpm during aggressive flight maneuvers Fault Test Conditions Continuous Possible Fault Causes Airframe collective pitch potentiometer mis rigged or failed intermittently Troubleshooting Prodedure See troubleshooting instructions for CPRgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 17 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File CPDFlt 73-25-04-127 Soft N/A N/A Fault Description This fault code not used in this application Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 18 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File CPFlt 73-25-04-113 Soft Parent CPFlt Fault Description The ECU has detected a problem with its collective pitch input used to maintain rotor rpm during aggressive flight maneuvers Fault Test Conditions Continuous Possible Fault Causes Airframe collective pitch potentiometer mis rigged or failed intermittently Troubleshooting Prodedure See troubleshooting instructions for CPRgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 19 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File CPRgFlt 73-25-04-113 Soft Child CPFlt Fault Description The ECU has detected a problem with its collective pitch input used to maintain rotor rpm during aggressive flight maneuvers Fault Test Conditions Continuous Possible Fault Causes Airframe collective pitch potentiometer mis rigged or failed intermittently Fault Limits Low High Open Circuit Reading -14.3% 110% CpRaw < -20% Special Limit Troubleshooting Prodedure Monitor CPRaw with collective full down and full up. If it fails out of range, rerig or replace collective potentiometer as required. If rigging is OK, perform some aircraft collective sweeps while on the ground at 100% Nr. Look at recorded graph of CPRaw for the signs of downward or upward spikes in the signal. If spikes are noticed, replace the collective potentiometer. Bell 407 FADEC System Troubleshooting Guide Page 20 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File ECUOTFlt 73-25-04-116 Hard Parent ECUOTFlt Fault Description The ECU has detected that its internal temperature, as measured by its cold junction, is extremely high Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure. Fault Limits Special Limit Low High Open Circuit Reading N/A 230°F N/A Troubleshooting Prodedure Record CJCRaw signal. Replace ECU and include value of CJCRaw signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 21 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File EECalFlt 73-25-04-116 Soft Child EECalFlt Fault Description The ECU has detected that the calibration constants used for its internal P1 pressure transducer and its Q input have changed from initial factory settings Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure. Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Record KinP1Gn, KinP1Cal, KinQGn and KinQCal values. Replace ECU and include values upon ECU return Bell 407 FADEC System Troubleshooting Guide Page 22 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File EEHistFlt 73-25-04-116 Soft Child N/A Fault Description The ECU has detected that the engine history data in its memory may be corrupted Fault Test Conditions Continuous Possible Fault Causes ECU write to historical EEPROM interrupted during engine shutdown causing erroneous history data to be written in memory Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Record engine history data on piece of paper. Clear all of the engine history. Cycle ECU power. Check for fault reoccurance. If fault is gone, edit original engine history back into the ECU. Cycle ECU power and check for fault reoccurance. Replace ECU if fault does not clear after this procedure. Bell 407 FADEC System Troubleshooting Guide Page 23 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File EEPROMFlt 73-25-04-116 Soft Parent N/A Fault Description The ECU has detected a problem with internal calibration or engine historical data Fault Test Conditions Continuous Possible Fault Causes ECU write to historical EEPROM interrupted during engine shutdown causing erroneous history data to be written in memory Troubleshooting Prodedure See troubleshooting for EECalFlt or EEHistFlt as appropriate Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 24 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File ForCompFlt 73-25-04-116 Soft Parent N/A Fault Description The ECU has detected that it has not completed its forground tasks within the allotted time period Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure. Very unlikely to occur. Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 25 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File FTempFlt 73-25-04-127 Soft N/A N/A Fault Description This fault code not used in this application Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 26 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File GainFlt 73-25-04-116 Hard Parent GainFlt Fault Description The ECU has detected a problem with a voltage reference used to process some of its input signals Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure See troubleshooting instructions for GainRgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 27 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File GainRgFlt 73-25-04-116 Hard Child GainFlt Fault Description The ECU has detected a problem with a voltage reference used to process some of its input signals Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading 2738 cnts 3019 cnts N/A Troubleshooting Prodedure Record GainVin signal. Replace ECU and include value of GainVin signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 28 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File HardFlt 73-25-04-128 Hard Parent N/A Fault Description The ECU has detected that a hard fault has occurred. This is the parent fault for all hard faults. Fault Test Conditions Continuous Possible Fault Causes Determined by any sub-tier hard fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure This fault will only appear when using the MT35 program. Troubleshoot sub-tier child hard faults to correct the problem. This fault is the parent of all hard faults. Bell 407 FADEC System Troubleshooting Guide Page 29 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File HLRfFlt 73-25-04-116 Hard Parent HLRfFlt Fault Description The ECU has detected a problem with a voltage reference used to process some of its input signals Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure See troubleshooting instructions for HLRfRgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 30 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File HLRfRgFlt 73-25-04-116 Hard Child HLRfFlt Fault Description The ECU has detected a problem with a voltage reference used to process some of its input signals Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading 3890 cnts 4077 cnts N/A Troubleshooting Prodedure Record HLRfRaw signal. Replace ECU and include value of HLRfRaw signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 31 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File IgnFlt 73-25-04-116 Soft Parent IgnFlt Fault Description The ECU has detected a problem with its control of the airframe igniter relay during an auto mode start attempt Fault Test Conditions N1 between 50 and 60% during start or during auto-relight. Possible Fault Causes Open circuit between airframe igniter relay return and ECU or an ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A ECU detects an open circuit on the return wire from the igniter relay Troubleshooting Prodedure Monitor IgnVBit after power up. Parameter should be FALSE. If TRUE, check for short on relay return wire to ECU. Perform auto mode engine start. At 50% N1, IgnVBit should become TRUE. If still FALSE, check for short to ground on relay return wire from airframe igniter relay. Bell 407 FADEC System Troubleshooting Guide Page 32 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File IgnIFlt 73-25-04-120 Soft Parent IgnIFlt Fault Description The ECU has detected a problem with its control of the airframe igniter relay prior to or during an auto mode start attempt Fault Test Conditions N1 between 50 and 60% during start or during auto-relight. Possible Fault Causes Faulty 1K3 FADEC Start Relay Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Airframe igniter relay current outside 0.015 amp and 0.4 amp range when relay is energized, relay current greater than 0.12 amp when relay should be off Troubleshooting Prodedure Monitor IgnIBitLag after power up. Current should be within limits when off. If not, replace ECU. If OK, select manual mode. Pull N1 indicator circuit breaker. Igniters should fire immediately. If not, troubleshoot wiring. If OK, swap FADEC Start Relay (1K3) with light dimming relay which is the same part number as the 1K3 relay. Perform auto mode engine start. Recheck for fault. If OK, problem is fixed. If not, depower aircraft. Remove airframe electrical connector at ECU. Select auto mode. With a jumper wire, ground Pin-7 to ECU ground strap. Apply power to aircraft. Igniters should fire immediately. If not, troubleshooting wiring as required. If OK, replace igniter relay. Bell 407 FADEC System Troubleshooting Guide Page 33 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File LoadSelFlt 73-25-04-127 Soft N/A N/A Fault Description This fault code not used in this application and applies only to twin engine applications Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 34 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File LoadSHdFlt 73-25-04-127 Soft N/A N/A Fault Description This fault code not used in this application and applies only to twin engine applications Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 35 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File MGTFlt 73-25-04-110 Soft Parent MGTFlt Fault Description The ECU has detected a problem with its MGT input signal Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the MGT thermocouple junction on the engine Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for either a MGTRgFlt or MGTRtFlt child fault Bell 407 FADEC System Troubleshooting Guide Page 36 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File MGTRgFlt 73-25-04-110 Soft Child MGTFlt Fault Description The ECU has detected a problem with its MGT input signal which has gone out of range Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the MGT thermocouple junction on the engine Fault Limits Low High Open Circuit Reading -77°F 2400°F MGTRaw > 2400 °F Troubleshooting Prodedure Monitor MGTRaw. If out of range high or low, check for open circuit between ECU and MGT thermocouple connection. Special Limit Bell 407 FADEC System Troubleshooting Guide Page 37 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File MGTRtFlt 73-25-04-110 Soft Child MGTFlt Fault Description The ECU has detected an intermittant problem with its MGT input signal Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the MGT thermocouple junction on the engine Fault Limits Low High Open Circuit Reading -77°F 2400°F MGTRaw > 2400 °F Troubleshooting Prodedure Monitor MGTRaw. If out of range high or low, check for open circuit between ECU and MGT thermocouple connection. Special Limit Bell 407 FADEC System Troubleshooting Guide Page 38 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Ng12Flt 73-25-04-109 Hard Parent NgFlts Fault Description The ECU has detected a problem with both the Ng1 and Ng2 speed input signals or difference exists between both Ng inputs Fault Test Conditions Np > 45% OR either Ng1 or Ng2 is between 10 and 130% Possible Fault Causes Loose or corroded connection at the N1 speed sensor on the engine Troubleshooting Prodedure See troubleshooting instructions for Ng related child faults Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Ng1 and Ng2 differ by more than 5% Bell 407 FADEC System Troubleshooting Guide Page 39 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Ng1CyFlt 73-25-04-109 Soft Child NgFlts Fault Description The ECU has detected a continuity problem with its Ng1 speed input signal Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the Ng1 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 8% 130% Ng1CyBit = OPEN Special Limit Ng fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Ng1CyBit upon power up. If OPEN, check for open circuit between ECU and Ng1 output of speed sensor. If OK, flex harness connections to attempt to duplicate the problem. Repair/replace effected component as required. Bell 407 FADEC System Troubleshooting Guide Page 40 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Ng1Flt 73-25-04-109 Soft Parent NgFlts Fault Description The ECU has detected a problem with its Ng1 speed input signal Fault Test Conditions Np > 45% OR either Ng1 or Ng2 is between 10 and 130% Possible Fault Causes Loose or corroded connection at the Ng1 speed sensor or a bad engine harness Troubleshooting Prodedure See troubleshooting instructions for Ng1 related child faults Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 41 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Ng1RgFlt 73-25-04-109 Soft Child NgFlts Fault Description The ECU has detected an open, shorted or intermittent problem with its Ng1 speed input signal Fault Test Conditions Np > 45% OR either Ng1 or Ng2 is between 10 and 130% Possible Fault Causes Loose or corroded connection at the Ng1 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 8% 130% Ng1CyBit = OPEN Special Limit Ng fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Ng1raw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze traces for signs of Ng1 signal fallout under various engine operating conditions. Replace Ng sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 42 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Ng1RtFlt 73-25-04-109 Soft Child NgFlts Fault Description The ECU has detected an intermittent problem with its Ng1 speed input signal Fault Test Conditions Np > 45% OR either Ng1 or Ng2 is between 10 and 130% Possible Fault Causes Loose or corroded connection at the Ng1 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 8% 130% Ng1CyBit = OPEN Special Limit Ng fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Ng1raw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze traces for signs of Ng1 signal fallout under various engine operating conditions. Replace Ng sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 43 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Ng2CyFlt 73-25-04-109 Soft Child NgFlts Fault Description The ECU has detected a continuity problem with its Ng2 speed input signal Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the Ng2 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 8% 130% Ng1CyBit = OPEN Special Limit Ng fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Ng2CyBit upon power up. If OPEN, check for open circuit between ECU and Ng2 output of speed sensor. If OK, flex harness connections to attempt to duplicate the problem. Repair/replace effected component as required. Bell 407 FADEC System Troubleshooting Guide Page 44 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Ng2Flt 73-25-04-109 Soft Parent NgFlts Fault Description The ECU has detected a problem with its Ng2 speed input signal Fault Test Conditions Np > 45% OR either Ng1 or Ng2 is between 10 and 130% Possible Fault Causes Loose or corroded connection at the Ng2 speed sensor or a bad engine harness Troubleshooting Prodedure See troubleshooting instructions for Ng2 related child faults Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 45 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Ng2RgFlt 73-25-04-109 Soft Child NgFlts Fault Description The ECU has detected an open, shorted or intermittent problem with its Ng2 speed input signal Fault Test Conditions Np > 45% OR either Ng1 or Ng2 is between 10 and 130% Possible Fault Causes Loose or corroded connection at the Ng2 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 8% 130% Ng2CyBit = OPEN Special Limit Ng fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Ng2raw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze traces for signs of Ng2 signal fallout under various engine operating conditions. Replace Ng sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 46 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Ng2RtFlt 73-25-04-109 Soft Child NgFlts Fault Description The ECU has detected an intermittent problem with its Ng2 speed input signal Fault Test Conditions Np > 45% OR either Ng1 or Ng2 is between 10 and 130% Possible Fault Causes Loose or corroded connection at the Ng2 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 8% 130% Ng2CyBit = OPEN Special Limit Ng fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Ng2raw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze traces for signs of Ng2 signal fallout under various engine operating conditions. Replace Ng sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 47 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NgDFlt 73-25-04-109 Hard Child NgFlts Fault Description The ECU has detected that its Ng1 and Ng2 inputs do not agree within 5% Fault Test Conditions Ng1 or Ng2 > 13% Possible Fault Causes Loose or corroded connection at the Ng1 or Ng2 speed sensor output or a bad engine harness Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Ng1 and Ng2 differ by more than 5% Troubleshooting Prodedure Monitor Ng1Raw and Ng2raw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze both Ng traces for signs of signal fallout under various engine operating conditions. Replace Ng sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 48 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NgOFlt 73-25-04-127 Soft N/A N/A Fault Description This fault code not used in this application and applies only to twin engine applications Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 49 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NgORgFlt 73-25-04-127 Soft N/A N/A Fault Description This fault code not used in this application and applies only to twin engine applications Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 50 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NgORtFlt 73-25-04-127 Soft N/A N/A Fault Description This fault code not used in this application and applies only to twin engine applications Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 51 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Np12Flt 73-25-04-108 Hard Parent NpFlts Fault Description The ECU has detected a problem with both the Np1 and Np2 speed input signals Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% Possible Fault Causes Loose or corroded connection at the N2 speed sensor on the engine Troubleshooting Prodedure See troubleshooting instructions for Np related child faults Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 52 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Np1CyFlt 73-25-04-108 Soft Child NpFlts Fault Description The ECU has detected a continuity problem with its Np1 speed input signal Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the Np1 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 20% 160% Np1CyBit = OPEN Special Limit Np fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Np1CyBit upon power up. If OPEN, check for open circuit between ECU and Np1 output of speed sensor. If OK, flex harness connections to attempt to duplicate the problem. Repair/replace effected component as required. Bell 407 FADEC System Troubleshooting Guide Page 53 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Np1Flt 73-25-04-108 Soft Parent NpFlts Fault Description The ECU has detected a problem with its Np1 speed input signal Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% Possible Fault Causes Loose or corroded connection at the Np1 speed sensor or a bad engine harness Troubleshooting Prodedure See troubleshooting instructions for Np1 related child faults Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 54 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Np1RgFlt 73-25-04-108 Soft Child NpFlts Fault Description The ECU has detected an open, shorted or intermittent problem with its Np1 speed input signal Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% Possible Fault Causes Loose or corroded connection at the Np1 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 20% 160% Np1CyBit = OPEN Special Limit Np fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Np1raw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze traces for signs of Np1 signal fallout under various engine operating conditions. Replace Np sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 55 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Np1RtFlt 73-25-04-108 Soft Child NpFlts Fault Description The ECU has detected an intermittent problem with its Np1 speed input signal Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% Possible Fault Causes Loose or corroded connection at the Np1 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 20% 160% Np1CyBit = OPEN Special Limit Np fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Np1raw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze traces for signs of Np1 signal fallout under various engine operating conditions. Replace Np sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 56 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Np2CyFlt 73-25-04-108 Soft Child NpFlts Fault Description The ECU has detected a continuity problem with its Np2 speed input signal Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the Np2 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 20% 160% Np1CyBit = OPEN Special Limit Np fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Np2CyBit upon power up. If OPEN, check for open circuit between ECU and Np2 output of speed sensor. If OK, flex harness connections to attempt to duplicate the problem. Repair/replace effected component as required. Bell 407 FADEC System Troubleshooting Guide Page 57 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Np2Flt 73-25-04-108 Soft Parent NpFlts Fault Description The ECU has detected a problem with its Np2 speed input signal Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% Possible Fault Causes Loose or corroded connection at the Np2 speed sensor or a bad engine harness Troubleshooting Prodedure See troubleshooting instructions for Np2 related child faults Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 58 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Np2RgFlt 73-25-04-108 Soft Child NpFlts Fault Description The ECU has detected an open, shorted or intermittent problem with its Np2 speed input signal Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% Possible Fault Causes Loose or corroded connection at the Np2 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 20% 160% Np2CyBit = OPEN Special Limit Np fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Np2raw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze traces for signs of Np2 signal fallout under various engine operating conditions. Replace Np sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 59 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Np2RtFlt 73-25-04-108 Soft Child NpFlts Fault Description The ECU has detected an intermittent problem with its Np2 speed input signal Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% Possible Fault Causes Loose or corroded connection at the Np2 speed sensor or a bad engine harness Fault Limits Low High Open Circuit Reading 20% 160% Np2CyBit = OPEN Special Limit Np fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Np2raw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze traces for signs of Np2 signal fallout under various engine operating conditions. Replace Np sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 60 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NpDFlt 73-25-04-108 Soft Parent NpFlts Fault Description The ECU has detected that its Np1 and Np2 inputs do not agree within 5% Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% Possible Fault Causes Loose or corroded connection at the Np1 or Np2 speed sensor output or a bad engine harness Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Np1 and Np2 differ by more than 5% Troubleshooting Prodedure Monitor Np1Raw and Np2raw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze both Np2 traces for signs of signal fallout under various engine operating conditions. Replace Np sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 61 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NpOSFlt 73-25-04-124 Soft Parent NpOSFlt Fault Description The ECU has detected that the Np speed frequency to voltage circuits within its overspeed circuitry are at Np levels which do not agree with actual Np speed from the speed pickups Fault Test Conditions Test active at Np > 55% or during overspeed system shutdown test Possible Fault Causes ECU internal failure. May be caused by an Np1Flt or Np2Flt so correcting the Np faults will fix the NpOSFlt Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Np speed from frequency to voltage conversion within ECU does not agree with actual Np within 2.5% Troubleshooting Prodedure If fault code is present with either an Np1Flt, Np2Flt or NpDFlt, follow troubleshooting for these faults first. If not, monitor signals with engine running at Nr = 100%. Before replacing the ECU, take a sample data trend and return the trend data with the ECU. Bell 407 FADEC System Troubleshooting Guide Page 62 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NpQExLmAdv 73-25-04-129 Soft Parent N/A Fault Description The ECU has detected an Np maximum limit exceedance > 113.3% for 1 second Fault Test Conditions Continuous when in run mode Possible Fault Causes Overspeed while controlling engine in manual mode, selection of manual mode on the ground with throttle in flight position Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Record NpQNppkExLm and NpQQpkExLm from ECU engine history. Perform engine maintenance as required. Bell 407 FADEC System Troubleshooting Guide Page 63 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NpQRnLmAdv 73-25-04-129 Soft Parent N/A Fault Description The ECU has detected an Np maximum run limit exceedance > 102.1% for 15s Fault Test Conditions Continuous when in run mode Possible Fault Causes Overspeed while controlling engine in manual mode, selection of manual mode on the ground with throttle in flight position Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Record NpQNppkRnLm and NpQQpkRnLm from ECU engine history. Perform engine maintenance as required. Bell 407 FADEC System Troubleshooting Guide Page 64 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NrAntDsb 73-25-04-114 Soft N/A N/A Fault Description This fault code not used in this application and applies only to twin engine applications Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 65 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NrCyFlt 73-25-04-114 Soft Child NrFlt Fault Description The ECU has detected a continuity problem with its Nr speed input signal Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the Nr speed sensor or a bad airframe harness Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Nr fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor NrCyBit upon power up. If OPEN, check for open circuit between ECU and Nr output of speed sensor. If OK, flex harness connections to attempt to duplicate the problem. Repair/replace effected component as required. Bell 407 FADEC System Troubleshooting Guide Page 66 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NrDFlt 73-25-04-127 Soft N/A N/A Fault Description This fault code not used in this application and applies only to twin engine applications Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 67 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NrFlt 73-25-04-114 Soft Parent NrFlt Fault Description The ECU has detected a problem with its Nr speed input signal Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% and engine not in test cell Possible Fault Causes Loose or corroded connection at the Nr speed sensor or a bad airframe harness Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for NrCyFlt or NrRgFlt child faults Bell 407 FADEC System Troubleshooting Guide Page 68 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NrRgFlt 73-25-04-114 Soft Child NrFlt Fault Description The ECU has detected an open, shorted or intermittent problem with its Nr speed input signal Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% and engine not in test cell Possible Fault Causes Loose or corroded connection at the Nr speed sensor or a bad airframe harness Fault Limits Low High Open Circuit Reading 40% 150% NrCyBit = OPEN Special Limit Nr fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Nrraw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze traces for signs of Nr signal fallout under various engine operating conditions. Replace Nr sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 69 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File NrRtFlt 73-25-04-114 Soft Child NrFlt Fault Description The ECU has detected an intermittent problem with its Nr speed input signal Fault Test Conditions Ng > 71% OR either Np1 or Np2 is between 45 and 160% and engine not in test cell Possible Fault Causes Loose or corroded connection at the Nr speed sensor or a bad airframe harness Fault Limits Low High Open Circuit Reading 40% 150% NrCyBit = OPEN Special Limit Nr fault detection includes continuous continuity (trickle curret) testing Troubleshooting Prodedure Monitor Nrraw with the engine operating at 100% Nr. Take a sample trend of the user defined screen and analyze traces for signs of Nr signal fallout under various engine operating conditions. Replace Nr sensor, wiring, etc. if fallout is noted. Bell 407 FADEC System Troubleshooting Guide Page 70 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OffsFlt 73-25-04-116 Hard Parent OffsFlt Fault Description The ECU has detected a problem with a voltage reference used to process some of its input signals Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure See troubleshooting instructions for OffsRgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 71 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OffsRgFlt 73-25-04-116 Hard Child OffsFlt Fault Description The ECU has detected a problem with a voltage reference used to process some of its input signals Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading 169 cnts 872 cnts N/A Troubleshooting Prodedure Record OffsRaw signal. Replace ECU and include value of OffsRaw signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 72 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OpenMvFlg 73-25-04-122 Soft Parent N/A Fault Description The ECU has detected that the HMU manual mode pistons are not properly parked Fault Test Conditions Test conducted at Ng < 8% while in start mode or shutdown Possible Fault Causes Engine last shutdown while in manual mode, airframe power turned off prematurely prior to a complete N1 coastdown Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A WfSel > 16 pph prior to start Troubleshooting Prodedure None required. Perform HMU piston parking procedure. Notify pilots to allow an additional 20s after VID N1 indication reaches 0% before turning off airframe power Bell 407 FADEC System Troubleshooting Guide Page 73 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Or28Flt 73-25-04-128 Soft Parent Or28Flt Fault Description The ECU has detected that the voltage at the output of its internal power selection diodes is out of range. The diodes select the higher voltage between the airframe bus and the PMA power input. The winner supplies the power to the ECU. Fault Test Conditions Continuous Possible Fault Causes Low airframe battery voltage upon power up. Troubleshooting Prodedure See troubleshooting instructions for Or28RgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Fault declared if voltage is out of range for at least 30 seconds Bell 407 FADEC System Troubleshooting Guide Page 74 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File Or28RgFlt 73-25-04-128 Soft Child Or28Flt Fault Description The ECU has detected that the voltage at the output of its internal power selection diodes is out of range. The diodes select the higher voltage between the airframe bus and the PMA power input. The winner supplies the power to the ECU. Fault Test Conditions Continuous Possible Fault Causes Low airframe battery voltage upon power up. Fault Limits Special Limit Low High Open Circuit Reading 7.5 vdc 60 vdc N/A Fault declared if voltage is out of range for at least 30 seconds Troubleshooting Prodedure Monitor Or28Raw and AF28Raw signals upon power up with airframe battery. If voltage is below low limit, replace/recharge battery, otherwise replace ECU with recorded value of AF28Raw and Or28Raw Bell 407 FADEC System Troubleshooting Guide Page 75 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OrDiodeFlt 73-25-04-116 Soft Parent OrDiodeFlt Fault Description The ECU has detected that the voltage drops across its internal power selection diodes is out of range. The diodes select the higher voltage between the airframe bus and the PMA power input. The winner supplies the power to the ECU. Fault Test Conditions Continuous Possible Fault Causes High airframe voltage upon power up due to improperly adjusted power cart, high voltage output of engine PMA Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Monitor signals after power up and check for excessively high voltage inputs. If none are noticed, run engine at 100% Nr and check for a high voltage output from the PMA on Al28Raw. Replace PMA if required. Otherwise, if ground power cart is set correctly, replace ECU. Bell 407 FADEC System Troubleshooting Guide Page 76 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSFlag 73-25-04-129 N/A N/A N/A Fault Description The ECU has detected that an Np overspeed has occurred whereby the HMU overspeed valve was energized to limit the Np speed Fault Test Conditions OSFlag declared if overspeed valve is energized while Np > 106% Possible Fault Causes Overspeed while controlling engine in manual mode, selection of manual mode on the ground with throttle in flight position Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Record NpQ exceedance values and OSCtr from ECU engine history. Perform engine maintenance as required. Bell 407 FADEC System Troubleshooting Guide Page 77 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSFlt 73-25-04-128 Soft Parent OSFlt Fault Description The ECU has detected a failure in its internal overspeed protection circuitry or the overspeed shutdown test has failed or its power up test of the overspeed system has failed. Fault Test Conditions Fault declared due to either a NPOSFlt, failure of the overspeed system shutdown or power up tests Possible Fault Causes See troubleshooting for NPOSFlt or other OS related child faults Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting for NPOSFlt or other OS related child faults Bell 407 FADEC System Troubleshooting Guide Page 78 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSI12Flt 73-25-04-104 Soft Child OSI12Flt Fault Description The ECU has detected a failure in the current flow from the HMU overspeed solenoid valve Fault Test Conditions Test conducted during overspeed system shutdown live test or upon power up with throttle off Possible Fault Causes Open circuit between HMU overspeed valve and ECU, or an ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Fault declared if solenoid current flow > 3 amps when HMU overspeed solenoid valve is on Troubleshooting Prodedure Monitor OSIBitRaw signal during overspeed shutdown test. If current is > 3 amps, check overspeed valve circuit resistance. Repair/replace wiring/HMU as required. If overspeed test does not shut the engine down, check for open circuit between HMU overspeed solenoid and ECU. Bell 407 FADEC System Troubleshooting Guide Page 79 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSTst1Flt 73-25-04-104 Soft Child OSFlt Fault Description The ECU has detected a failure in its ability to control the HMU overspeed solenoid valve during its power up test Fault Test Conditions Test conducted during power up with throttle off in auto mode Possible Fault Causes Open/short circuit between HMU overspeed valve and ECU, or an ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Apply power to aircraft with FADEC mode switch in manual and the throttle off. Start a signal trend and select auto mode. Retain data. Check for open/short ciruit between ECU and HMU overspeed solenoid. Repair/replace wiring as necessary. Bell 407 FADEC System Troubleshooting Guide Page 80 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSTst2Flt 73-25-04-104 Soft Child OSFlt Fault Description The ECU has detected a failure in its ability to control the HMU overspeed solenoid valve during its power up test Fault Test Conditions Test conducted during power up with throttle off in auto mode Possible Fault Causes Open/short circuit between HMU overspeed valve and ECU, or an ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Apply power to aircraft with FADEC mode switch in manual and the throttle off. Start a signal trend and select auto mode. Retain data. Check for open/short ciruit between ECU and HMU overspeed solenoid. Repair/replace wiring as necessary. Bell 407 FADEC System Troubleshooting Guide Page 81 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSTst3Flt 73-25-04-104 Soft Child OSFlt Fault Description The ECU has detected a failure in its ability to control the HMU overspeed solenoid valve during its power up test Fault Test Conditions Test conducted during power up with throttle off in auto mode Possible Fault Causes Open/short circuit between HMU overspeed valve and ECU, or an ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Apply power to aircraft with FADEC mode switch in manual and the throttle off. Start a signal trend and select auto mode. Retain data. Check for open/short ciruit between ECU and HMU overspeed solenoid. Repair/replace wiring as necessary. Bell 407 FADEC System Troubleshooting Guide Page 82 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSTst4Flt 73-25-04-104 Soft Child OSFlt Fault Description The ECU has detected a failure in its ability to control the HMU overspeed solenoid valve during its power up test Fault Test Conditions Test conducted during power up with throttle off in auto mode Possible Fault Causes Open/short circuit between HMU overspeed valve and ECU, or an ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Apply power to aircraft with FADEC mode switch in manual and the throttle off. Start a signal trend and select auto mode. Retain data. Check for open/short ciruit between ECU and HMU overspeed solenoid. Repair/replace wiring as necessary. Bell 407 FADEC System Troubleshooting Guide Page 83 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSTst5Flt 73-25-04-104 Soft Child OSFlt Fault Description The ECU has detected a failure in its ability to control the HMU overspeed solenoid valve during its power up test Fault Test Conditions Test conducted during power up with throttle off in auto mode Possible Fault Causes Open/short circuit between HMU overspeed valve and ECU, or an ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Apply power to aircraft with FADEC mode switch in manual and the throttle off. Start a signal trend and select auto mode. Retain data. Check for open/short ciruit between ECU and HMU overspeed solenoid. Repair/replace wiring as necessary. Bell 407 FADEC System Troubleshooting Guide Page 84 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSTst6Flt 73-25-04-104 Soft Child OSFlt Fault Description The ECU has detected a failure in its ability to control the HMU overspeed solenoid valve during its power up test Fault Test Conditions Test conducted during power up with throttle off in auto mode Possible Fault Causes Open/short circuit between HMU overspeed valve and ECU, or an ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Apply power to aircraft with FADEC mode switch in manual and the throttle off. Start a signal trend and select auto mode. Retain data. Check for open/short ciruit between ECU and HMU overspeed solenoid. Repair/replace wiring as necessary. Bell 407 FADEC System Troubleshooting Guide Page 85 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSTst7Flt 73-25-04-104 Soft Child OSFlt Fault Description The ECU has detected a failure in its ability to control the HMU overspeed solenoid valve during its power up test Fault Test Conditions Test conducted during power up with throttle off in auto mode Possible Fault Causes Open/short circuit between HMU overspeed valve and ECU, or an ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Apply power to aircraft with FADEC mode switch in manual and the throttle off. Start a signal trend and select auto mode. Retain data. Check for open/short ciruit between ECU and HMU overspeed solenoid. Repair/replace wiring as necessary. Bell 407 FADEC System Troubleshooting Guide Page 86 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSTstFlt 73-25-04-123 Soft Child OSFlt Fault Description The ECU has detected a failure of the HMU during an overspeed system shutdown test Fault Test Conditions Test conducted during aircraft overspeed system shutdown test Possible Fault Causes HMU failure or test conducted at high altitude. Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Replace HMU or repeat overspeed system shutdown test at a lower altitude. Fault declared if N1 speed does not decrease by more that 1% when HMU solenoid valve is energized Bell 407 FADEC System Troubleshooting Guide Page 87 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSTstSwFlt 73-25-04-118 Soft Child OSTstSwFlt Fault Description The ECU has detected a failure of the cockpit overspeed test switch Fault Test Conditions Continuous Possible Fault Causes Overspeed test switch stuck closed or held in too long during shutdown test. Fault declared if Overspeed test switch pressed or shorted for more than 30s. Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Fault declared if cockpit test switch closed for more that 30 sec Troubleshooting Prodedure Monitor OSTestSw while pressing and releasing the test switch. When switch is pressed, OSTestSw should be TRUE. When released it should be FALSE. When pressed, a ground should be sensed at the input. When released, the input should be open circuit. The fault will be declared if the ECU senses that the switch is held in or shorted for more than 30s. Replace switch/repair wiring as required. Bell 407 FADEC System Troubleshooting Guide Page 88 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSVFlt 73-25-04-116 Soft Parent OSVFlt Fault Description The ECU has detected a problem with a voltage reference used within its overspeed protection circuitry Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure See troubleshooting instructions for OSVRgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 89 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File OSVRgFlt 73-25-04-116 Soft Child OSVFlt Fault Description The ECU has detected a problem with a voltage reference used within its overspeed protection circuitry Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading 4.5 vdc 6.0 vdc N/A Troubleshooting Prodedure Record OSVRaw signal. Replace ECU and include value of OSVRaw signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 90 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File P1DFlt 73-25-04-127 Soft N/A N/A Fault Description This fault code not used in this application and applies only to twin engine applications Fault Test Conditions Possible Fault Causes ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared. Bell 407 FADEC System Troubleshooting Guide Page 91 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File P1Flt 73-25-04-115 Soft Parent P1Flt Fault Description The ECU has detected a failure of its internal P1 ambient pressure transducer Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for P1RgFlt or P1RtFlt child faults Bell 407 FADEC System Troubleshooting Guide Page 92 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File P1HdFlt 73-25-04-115 Hard Parent P1Flt Fault Description The ECU has detected a failure of its internal P1 ambient pressure transducer and can not calculate a syntesized P1 to accommodate the failure Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure and a Q failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Record P1Raw signal. Replace ECU and include value of P1Raw signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 93 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File P1RgFlt 73-25-04-115 Soft Child P1Flt Fault Description The ECU has detected a failure of its internal P1 ambient pressure transducer where its P1 signal was out of range Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading 5 psia 16 psia N/A Troubleshooting Prodedure Record P1Raw signal. Replace ECU and include value of P1Raw signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 94 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File P1RtFlt 73-25-04-115 Soft Child P1Flt Fault Description The ECU has detected a failure of its internal P1 ambient pressure transducer where its P1 signal failed at a high rate of change Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading 5 psia 16 psia N/A Troubleshooting Prodedure Record P1Raw signal. Replace ECU and include value of P1Raw signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 95 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PLA12Flt 73-25-04-106 Soft Parent PLAFlts Fault Description The ECU has detected that both throttle inputs have failed or that they do not agree within 5 degrees Fault Test Conditions Continuous Possible Fault Causes HMU PLA potentiometer failure or throttle min/max stops on HMU quadrant shifted during initial HMU installation Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for PLA1RgFlt or PLA2RgFlt child faults Bell 407 FADEC System Troubleshooting Guide Page 96 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PLA1Flt 73-25-04-106 Soft Parent PLAFlts Fault Description The ECU has detected that its PLA1 input has failed Fault Test Conditions Continuous Possible Fault Causes HMU PLA potentiometer failure or throttle min/max stops on HMU quadrant shifted during initial HMU installation Troubleshooting Prodedure See troubleshooting instructions for PLA1RgFlt Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 97 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PLA1RgFlt 73-25-04-106 Soft Child PLAFlts Fault Description The ECU has detected that its PLA1 input has failed out of range Fault Test Conditions Continuous Possible Fault Causes HMU PLA potentiometer failure or throttle min/max stops on HMU quadrant shifted during initial HMU installation Fault Limits Low High Open Circuit Reading -5 deg 110 deg PLA1Raw > 120° Special Limit Troubleshooting Prodedure Monitor signals when throttle position at cutoff and fly. Check PLA1 and PLA2 values against range limits. Replace HMU if values near range limits. If PLA range is OK, trend data while manipulating throttle between cutoff and fly back to cutoff repeatedly for 60 seconds. Analyze data traces for signs of spikes on graphs. If spikes are noticed, replace HMU. Bell 407 FADEC System Troubleshooting Guide Page 98 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PLA2Flt 73-25-04-106 Soft Parent PLAFlts Fault Description The ECU has detected that its PLA2 input has failed Fault Test Conditions Continuous Possible Fault Causes HMU PLA potentiometer failure or throttle min/max stops on HMU quadrant shifted during initial HMU installation Troubleshooting Prodedure See troubleshooting instructions for PLA1RgFlt Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 99 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PLA2RgFlt 73-25-04-106 Soft Child PLAFlts Fault Description The ECU has detected that its PLA2 input has failed out of range Fault Test Conditions Continuous Possible Fault Causes HMU PLA potentiometer failure or throttle min/max stops on HMU quadrant shifted during initial HMU installation Fault Limits Low High Open Circuit Reading -5 deg 110 deg PLA2Raw > 120° Special Limit Troubleshooting Prodedure Monitor signals when throttle position at cutoff and fly. Check PLA1 and PLA2 values against range limits. Replace HMU if values near range limits. If PLA range is OK, trend data while manipulating throttle between cutoff and fly back to cutoff repeatedly for 60 seconds. Analyze data traces for signs of spikes on graphs. If spikes are noticed, replace HMU. Bell 407 FADEC System Troubleshooting Guide Page 100 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PLADFlt 73-25-04-106 Soft Parent PLAFlts Fault Description The ECU has detected that both throttle inputs do not agree within 5 degrees Fault Test Conditions Continuous Possible Fault Causes ECU failure or wiring problem between ECU and HMU PLA potentiometer Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Fault declared if PLA1 and PLA2 are not within 5 degrees of eachother Troubleshooting Prodedure Monitor signals when throttle position at cutoff and fly. Compare PLA1 and PLA2 values against eachother. If they don't agree, check the wiring between the ECU and HMU PLA pot for the signal which does not agree with the physical throttle postion. If they agree, trend data while manipulating throttle between cutoff and fly back to cutoff repeatedly for 60 seconds. Analyze data traces for signs of spikes on graphs. If spikes are noticed, replace the ECU. Bell 407 FADEC System Troubleshooting Guide Page 101 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PLAHdFlt 73-25-04-106 Hard Parent PLAFlts Fault Description The ECU has detected that both throttle inputs have failed or that they do not agree within 5 degrees prior to the throttle reaching the flight position or the problem exists when the engine is shutdown or on powerup Fault Test Conditions Continuous Possible Fault Causes HMU PLA potentiometer failure or throttle min/max stops on HMU quadrant shifted during initial HMU installation Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Monitor signals when throttle position at cutoff and fly. Check PLA1 and PLA2 values against range limits. Replace HMU if values near range limits. If PLA range is OK, trend data while manipulating throttle between cutoff and fly back to cutoff repeatedly for 60 seconds. Analyze data traces for signs of spikes on graphs. If spikes are noticed, replace HMU. Bell 407 FADEC System Troubleshooting Guide Page 102 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PLARfFlt 73-25-04-106 Soft Parent PLAFlts Fault Description The ECU has detected that the voltage supply reference to the HMU PLA potentiometer has failed Fault Test Conditions Continuous Possible Fault Causes ECU Failure or shorted wiring between ECU and HMU PLA potentiometer Troubleshooting Prodedure See troubleshooting instructions for PLARfRgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 103 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PLARfRgFlt 73-25-04-106 Soft Child PLAFlts Fault Description The ECU has detected that the voltage supply reference to the HMU PLA potentiometer has failed out of range Fault Test Conditions Continuous Possible Fault Causes ECU Failure or shorted wiring between ECU and HMU PLA potentiometer Fault Limits Special Limit Low High Open Circuit Reading 4.95 vdc 5.05 vdc N/A Troubleshooting Prodedure Monitor PLARfRaw signal with engine harness disconnected from ECU and when it is connected to the ECU. If no change in PLA reference voltage and the reference is out of limits, replace the ECU. If in limits only when harness is disconnected, check for short circuit between ECU and HMP +5V PLA supply wiring. Replace/repair effected component as required. Bell 407 FADEC System Troubleshooting Guide Page 104 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PROMFlt 73-25-04-116 Hard Parent N/A Fault Description The ECU has detected that its program checksum does not agree with the value stored at the factory Fault Test Conditions Power up and background tasks Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Record value of ID on the MT35 program header and return ECU with ID value. The ID value should be 443F. Bell 407 FADEC System Troubleshooting Guide Page 105 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PW10Flt 73-25-04-116 Hard Parent PW10Flts Fault Description The ECU has detected a failure of its internal pulse width modulated voltage used to control the +28V dc supply output to the HMU stepper motor Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure See troubleshooting instructions for PW10RgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 106 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File PW10RgFlt 73-25-04-116 Hard Child PW10Flts Fault Description The ECU has detected a failure of its internal pulse width modulated voltage used to control the +28V dc supply output to the HMU stepper motor Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading 6.5 vdc 11 vdc N/A Troubleshooting Prodedure Record value of PW10Raw signal and return ECU with PW10Raw value Bell 407 FADEC System Troubleshooting Guide Page 107 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File QFlt 73-25-04-112 Soft Parent QFlt Fault Description The ECU has detected a problem with its torque input signal or has determined the torque input is invalid Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the TMOP sensor on the engine, oil in TMOP sensor connection, bad TMOP sensor Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for either a QRgFlt or QRtFlt child fault Bell 407 FADEC System Troubleshooting Guide Page 108 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File QRgFlt 73-25-04-112 Soft Child QFlt Fault Description The ECU has detected a problem with its torque input signal which has gone out of range Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the TMOP sensor on the engine, oil in TMOP sensor connection, bad TMOP sensor Fault Limits Special Limit Low High Open Circuit Reading -10% 200% QRaw > 200% Low limit of 5% if N1 > 85% under steady state conditions Troubleshooting Prodedure Monitor QRaw. If out of range high or low, check for open circuit between ECU and engine TMOP sensor connection. If normal, run engine at 100% Nr and compare Qraw indication to that of the cockpit after scaling cockpit reading. If they differ substantially, replace TMOP sensor. Take a trend under these condtions and look for spikes on the Qraw trace while flexing harnesses. Replace wiring as required. Bell 407 FADEC System Troubleshooting Guide Page 109 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File QRtFlt 73-25-04-112 Soft Child QFlt Fault Description The ECU has detected an intermittant problem with its torque input signal Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the TMOP sensor on the engine, oil in TMOP sensor connection, bad TMOP sensor Fault Limits Special Limit Low High Open Circuit Reading -10% 200% Qraw > 200% Low limit of 5% if N1 > 85% under steady state conditions Troubleshooting Prodedure Monitor QRaw. If out of range high or low, check for open circuit between ECU and engine TMOP sensor connection. If normal, run engine at 100% Nr and compare Qraw indication to that of the cockpit after scaling cockpit reading. If they differ substantially, replace TMOP sensor. Take a trend under these condtions and look for spikes on the Qraw trace while flexing harnesses. Replace wiring as required. Bell 407 FADEC System Troubleshooting Guide Page 110 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File QSwFlt 73-25-04-156 Soft Parent QMSwFlt Fault Description The ECU has detected a problem with the FADEC Quiet Mode switch (Optional) Fault Test Conditions Continuous Possible Fault Causes Bad FADEC quiet mode select switch or wiring from the switch to the ECU. Corrosion/moisture in airframe harness. Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Fault is declared if the ECU detects that both quiet mode switch inputs do not agree. Troubleshooting Prodedure Monitor QMSw1 and QMSw2. When not in quiet mode, both should be FALSE. Select quiet mode. Both should be TRUE. A grounded input makes the input TRUE. An open input makes the input FALSE. Both inputs should be the same simultaneously. Troubleshoot switch and wiring as applicable. Bell 407 FADEC System Troubleshooting Guide Page 111 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File QVldFlt 73-25-04-112 Soft Child QVldFlt Fault Description The ECU has determined that its torque input signal is invalid when it is compared to theoretical engine shaft horsepower determined from N1 speed Fault Test Conditions Continuous Possible Fault Causes Air trapped in TMOP sensor supply tube from the engine gearbox, bad TMOP sensor or erroneous P1 or T1 input to the DECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Np times Q times 0.06 > estimated engine horsepower as a function of N1 corrected speed Troubleshooting Prodedure Monitor QRaw, P1 and T1 when engine running at 100% Nr. Check if P1 and T1 are consistant with actual ambient conditions. If P1 is not reading correctly, replace the ECU. If T1 is not reading correctly, replace the engine T1 sensor. Otherwise, replace the TMOP sensor after first checking for air within the TMOP transducer supply tube from the gearbox. Bleed any air and recheck. Bell 407 FADEC System Troubleshooting Guide Page 112 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File RAMFlt 73-25-04-116 Hard Parent N/A Fault Description The ECU has detected a problem with its internal Random Access Memory (RAM) Fault Test Conditions Power up and background tasks Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 113 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File SgFlag See AMM Soft N/A N/A Fault Description The ECU has detected that the engine has surged Fault Test Conditions Continuous when in engine run mode Possible Fault Causes Inefficient engine compressor or faulty bleed band actuator Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Record the value of SgCtr in ECU engine history. Check for ECU MGT exceedances. Check engine compressor for signs of FOD damage or erosion. Check for proper closure and operation of the engine bleed band actuator Bell 407 FADEC System Troubleshooting Guide Page 114 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File SMFlt 73-25-04-101 Hard Parent SMFlt Fault Description The ECU has detected a problem with its control of the HMU stepper motor Fault Test Conditions Power up test only with throttle off Possible Fault Causes Wiring problem between ECU and HMU stepper motor Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for SmPhAVFlt, SmPhBVFlt, SmPhCVFlt, SmPhDVFlt or SmPhIFlt child faults Bell 407 FADEC System Troubleshooting Guide Page 115 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File SMPhAVFlt 73-25-04-101 Hard Child SMFlt Fault Description The ECU has detected a problem with the control of phase A of the HMU stepper motor Fault Test Conditions Power up test only with throttle off Possible Fault Causes Wiring problem between ECU and HMU stepper motor phase A return. Internal ECU phase A driver failure. Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Apply power to aircraft with FADEC mode switch in manual. Check that all SmPh voltage bits are false. If SmPhAVbit is TRUE, check for ground in wiring from ECU to HMU stepper motor phase A. If SmPhAVbit is FALSE, select auto mode with throttle in cutoff and take trend data. Compare the SmTstCnt value against the states of the SmPh voltage bits as follows: SmTstCnt (1-4: All Vbits FALSE), SmTstCnt (5-8: SmPhAVbit = TRUE), SmTstCnt (9-12: SmPhBVbit = TRUE), SmTstCnt (13-16: SmPhCVbit = TRUE), SmTstCnt (17-20: SmPhDVbit = TRUE), SmTstCnt (21: SmPhCVbit = TRUE), SmTstCnt (22: SmPhBVbit = TRUE), SmTstCnt (23: SmPhAVbit = TRUE), SmTstCnt (24: All Vbits = FALSE). Check for open/short ciruit in wiring on effected stepper motor phase. Bell 407 FADEC System Troubleshooting Guide Page 116 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File SMPhBVFlt 73-25-04-101 Hard Child SMFlt Fault Description The ECU has detected a problem with the control of phase B of the HMU stepper motor Fault Test Conditions Power up test only with throttle off Possible Fault Causes Wiring problem between ECU and HMU stepper motor phase B return. Internal ECU phase B driver failure. Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Follow troubleshooting instructions for SmPhAVFlt referencing SmPhBVbit Bell 407 FADEC System Troubleshooting Guide Page 117 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File SMPhCVFlt 73-25-04-101 Hard Child SMFlt Fault Description The ECU has detected a problem with the control of phase C of the HMU stepper motor Fault Test Conditions Power up test only with throttle off Possible Fault Causes Wiring problem between ECU and HMU stepper motor phase C return. Internal ECU phase C driver failure. Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Follow troubleshooting instructions for SmPhAVFlt referencing SmPhCVbit Bell 407 FADEC System Troubleshooting Guide Page 118 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File SMPhDVFlt 73-25-04-101 Hard Child SMFlt Fault Description The ECU has detected a problem with the control of phase D of the HMU stepper motor Fault Test Conditions Power up test only with throttle off Possible Fault Causes Wiring problem between ECU and HMU stepper motor phase D return. Internal ECU phase D driver failure. Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Follow troubleshooting instructions for SmPhAVFlt referencing SmPhDVbit Bell 407 FADEC System Troubleshooting Guide Page 119 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File SMPhIFlt 73-25-04-101 Hard Child SMFlt Fault Description The ECU has detected a problem with current flow from on of the HMU stepper motor phases Fault Test Conditions Power up test only with throttle off Possible Fault Causes Wiring problem between ECU and HMU stepper motor. Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A SmIBitRaw not between 0.1 amp and 1.5 amp when phase turned on. SmIBitRaw > 0.2 amp when phase supposedly off. Troubleshooting Prodedure Apply power to aircraft with FADEC mode switch in manual. Check that SmIBitRaw is less than 0.2 amps. If greater, check wiring from ECU to HMU stepper motor. If OK, select auto mode with the throttle in cutoff and take trend data. Compare the SmTstCnt value against the SmIBitRaw value as follows: SmTstCnt (1-4: no current), SmTstCnt (5-8: current from phase A), SmTstCnt (9-12: current from phase B), SmTstCnt (13-16: current from phase C), SmTstCnt (17-20: current from phase D), SmTstCnt (21:current from phase C), SmTstCnt (22: current from phase B), SmTstCnt (23: current from phase A), SmTstCnt (24: no current). Check for open/short circuit in wiring on effected stepper motor phase. Bell 407 FADEC System Troubleshooting Guide Page 120 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File StepCntFlt 73-25-04-121 Hard Parent StepCntFlt Fault Description The ECU has detected that the HMU stepper is not moving when commanded to move Fault Test Conditions Continuous when engine is running (start or run mode) If this fault occurs, a WFhdFlt will also be declared which is not resettable by cycling the FADEC mode switch, only by cycling ECU power. Possible Fault Causes Auto start attempt after initial HMU installation on engine with insufficient HMU fuel bleed procedure, engine auto start attempted after engine shutdown in manual mode without subsequent piston parking procedure performed, wiring problem affecting HMU Wf feedback signal, HMU stepper motor failure, HMU Wf feedback potentiometer failure, wiring problem between ECU and HMU stepper motor or auto/manual solenoid Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Difference between WfmvRaw fuel flow and Wfstp stepcount fuel flow greater than 42 PPH Troubleshooting Prodedure Check if the fault was possibly caused by procedural error as identified in fault probable causes. Monitor WfmvRaw parameter while flexing electrical harnesses and taking trend data. Analyze trace for signs of Wfmvraw instability from its nominal -10 pph position at power up. If the signal changes with flexing, repair/replace wiring. Select manual mode. Trend data while flexing harnesses. Ensure that no SM Vbits change to TRUE during the flexing. Check wiring between ECU and HMU stepper motor and auto/manual solenoid per instructions provided for AMSolFlt and SMFlt. If faulty grounded wiring is found on any of the HMU stepper motor phase returns, the HMU may be damaged internally. If electrical checks pass, replace HMU. Bell 407 FADEC System Troubleshooting Guide Page 121 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File StrFlt 73-25-04-116 Soft Parent StrFlt Fault Description The ECU has detected a problem with its control of the airframe starter relay during an auto mode start attempt Fault Test Conditions Start switch pressed in auto mode during start or auto-relight Possible Fault Causes Open circuit between airframe starter relay return and ECU or an ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A ECU detects an open circuit on the return wire from the starter relay Troubleshooting Prodedure Monitor StrVBit after power up. Parameter should be FALSE. If TRUE, check for short on relay return wire to ECU. Next, motor engine to 10% N1. StrVbit should become TRUE when start switch is pressed. If still FALSE, check for open circuit on relay return wire from airframe starter relay. Bell 407 FADEC System Troubleshooting Guide Page 122 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File StSFlt 73-25-04-102 Soft Parent StSFlt Fault Description The ECU has detected a problem with its control of the HMU start fuel solenoid Fault Test Conditions In auto mode, StSIbitRaw current > 0.08 amps when engine off or ECU detects that the start fuel solenoid is on with the engine off or it is not on when commanded during an auto mode start attemp at 10% N1 Possible Fault Causes Grounded wire between ECU and return from HMU start fuel solenoid Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A In auto mode, StSIbitRaw current > 0.08 amps when engine off or ECU detects that the start fuel solenoid is on with the engine off or it is not on when commanded during an auto mode start attemp at 10% N1 Troubleshooting Prodedure Monitor STSVBit after power up. Parameter should be FALSE. If TRUE, check for short on return wire from HMU start fuel solenoid to the ECU. STSIbitRaw should by less than 0.08 amps. If not, check wiring for cross short to ECU start fuel solenoid return. If all OK, perform auto mode start and trend data. Check that STSVbit changes to TRUE when STSEnb changes to TRUE. If not, check for open circuit between ECU and return of HMU start fuel solenoid. Bell 407 FADEC System Troubleshooting Guide Page 123 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File StSIFlt 73-25-04-102 Soft Parent StSFlt Fault Description The ECU has detected a problem with the current flow from the HMU start fuel solenoid Fault Test Conditions In auto mode, StSIbitRaw current not between 0.05 amp and 1.0 amp when HMU start fuel solenoid energized Possible Fault Causes Grounded or open wire between ECU and return from HMU start fuel solenoid Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A In auto mode, StSIbitRaw current not between 0.05 amp and 1.0 amp when HMU start fuel solenoid energized Troubleshooting Prodedure Monitor STSIBitRaw after power up. Motor the engine without ignition to 15% N1. Check that STSIBitRaw changes to within its current range at 10% N1. If not, check for open or short circuit between ECU and return of HMU start fuel solenoid. Repair as required. Bell 407 FADEC System Troubleshooting Guide Page 124 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File SWIntFlt 73-25-04-116 Soft Parent N/A Fault Description The ECU has detected that abnormal software interrupts have occurred Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 125 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File T1ABFlt 73-25-04-107 Hard Parent T1Flts Fault Description The ECU has detected that both T1 ambient temperature inputs have failed or that they do not agree within 30°F Fault Test Conditions Continuous Possible Fault Causes Engine T1 sensor connection loose or corroded, T1 sensor failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for T1ARgFlt, T1ARtFlt, T1BRgFlt and T1BRtFlt child faults Bell 407 FADEC System Troubleshooting Guide Page 126 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File T1AFlt 73-25-04-107 Soft Parent T1Flts Fault Description The ECU has detected a failure in its T1A ambient temperature input Fault Test Conditions Continuous Possible Fault Causes Engine T1A sensor output wiring loose or corroded Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for T1ARgFlt and T1ARtFlt child faults Bell 407 FADEC System Troubleshooting Guide Page 127 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File T1ARgFlt 73-25-04-107 Soft Child T1Flts Fault Description The ECU has detected a failure in its T1A ambient temperature input which has gone out of range Fault Test Conditions Continuous Possible Fault Causes Engine T1A sensor output wiring loose or corroded Fault Limits Low High Open Circuit Reading -75°F 225°F T1ARaw < -90 °F Special Limit Difference between T1ARaw and T1BRaw > 30°F Troubleshooting Prodedure Monitor T1ARaw after powerup. Open circuit indicated if T1ARaw < -90°F. Repair as required. If T1ARaw is normal after powerup, flex harness while taking trend data. Analyze trace for signs of sensor output instability. Repair as required. Bell 407 FADEC System Troubleshooting Guide Page 128 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File T1ARtFlt 73-25-04-107 Soft Child T1Flts Fault Description The ECU has detected a failure in its T1A ambient temperature input which was intermittant Fault Test Conditions Continuous Possible Fault Causes Engine T1A sensor output wiring loose or corroded Fault Limits Low High Open Circuit Reading -75°F 225°F T1ARaw < -90 °F Special Limit Difference between T1ARaw and T1BRaw > 30°F Troubleshooting Prodedure Monitor T1ARaw after powerup. Open circuit indicated if T1ARaw < -90°F. Repair as required. If T1ARaw is normal after powerup, flex harness while taking trend data. Analyze trace for signs of sensor output instability. Repair as required. Bell 407 FADEC System Troubleshooting Guide Page 129 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File T1BFlt 73-25-04-107 Soft Parent T1Flts Fault Description The ECU has detected a failure in its T1B ambient temperature input Fault Test Conditions Continuous Possible Fault Causes Engine T1B sensor output wiring loose or corroded Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for T1BRgFlt and T1BRtFlt child faults Bell 407 FADEC System Troubleshooting Guide Page 130 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File T1BRgFlt 73-25-04-107 Soft Child T1Flts Fault Description The ECU has detected a failure in its T1B ambient temperature input which has gone out of range Fault Test Conditions Continuous Possible Fault Causes Engine T1B sensor output wiring loose or corroded Fault Limits Low High Open Circuit Reading -75°F 225°F T1BRaw < -90 °F Special Limit Difference between T1ARaw and T1BRaw > 30°F Troubleshooting Prodedure Monitor T1BRaw after powerup. Open circuit indicated if T1BRaw < -90°F. Repair as required. If T1BRaw is normal after powerup, flex harness while taking trend data. Analyze trace for signs of sensor output instability. Repair as required. Bell 407 FADEC System Troubleshooting Guide Page 131 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File T1BRtFlt 73-25-04-107 Soft Child T1Flts Fault Description The ECU has detected a failure in its T1B ambient temperature input which was intermittant Fault Test Conditions Continuous Possible Fault Causes Engine T1B sensor output wiring loose or corroded Fault Limits Low High Open Circuit Reading -75°F 225°F T1BRaw < -90 °F Special Limit Difference between T1ARaw and T1BRaw > 30°F Troubleshooting Prodedure Monitor T1BRaw after powerup. Open circuit indicated if T1BRaw < -90°F. Repair as required. If T1BRaw is normal after powerup, flex harness while taking trend data. Analyze trace for signs of sensor output instability. Repair as required. Bell 407 FADEC System Troubleshooting Guide Page 132 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File T1DFlt 73-25-04-107 Hard Parent T1Flts Fault Description The ECU has detected that both T1 ambient temperature inputs do not agree within 30°F Fault Test Conditions Continuous Possible Fault Causes Engine T1 sensor connection loose or corroded, T1 sensor failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for T1ARgFlt, T1ARtFlt, T1BRgFlt and T1BRtFlt child faults Difference between T1ARaw and T1BRaw > 30°F Bell 407 FADEC System Troubleshooting Guide Page 133 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File TempFlt 73-25-04-128 Soft Parent N/A Fault Description The ECU has detected a problem with its MGT input signal or its internal cold junction used to compensate the MGT input Fault Test Conditions Continuous Possible Fault Causes Loose or corroded connection at the MGT thermocouple junction on the engine or internal ECU failure Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for either a MGTFlt or CJCFlt child fault. TempFlt name only viewable with MT35 maintenance software Bell 407 FADEC System Troubleshooting Guide Page 134 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File TestCelFlt 73-25-04-126 Soft Parent TestCelFlt Fault Description The ECU has detected that its test cell input is grounded but it is still getting a rotor speed input Fault Test Conditions Test for grounded Testcell input when Nr > 50% Possible Fault Causes Erroneous ground on ECU TestCell Input Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure Monitor value of TestCell after powerup. Trend data while flexing harness. Analayze trend data. TestCell should always be FALSE. If TRUE, check wiring for ground in harness on pin P2-58. Bell 407 FADEC System Troubleshooting Guide Page 135 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File UARTFlt 73-25-04-116 Soft Parent N/A Fault Description The ECU has detected a problem with its RS-423 interface during its power up self test and/or background tests Fault Test Conditions Power up or during background tasks Possible Fault Causes Internal ECU Failure. Very unlikely to occur. Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 136 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File UUIntFlt 73-25-04-116 Soft Parent N/A Fault Description The ECU has detected that a software interrupt occurred from one which has not been assigned by the software Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 137 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File V15Flt 73-25-04-116 Hard Parent V15Flt Fault Description The ECU has detected a problem with an internal 15 volt dc power supply reference Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure See troubleshooting instructions for V15RgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 138 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File V15RgFlt 73-25-04-116 Hard Child V15Flt Fault Description The ECU has detected a problem with an internal 15 volt dc power supply reference Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading 2.4 vdc 3.6 vdc N/A Troubleshooting Prodedure Record V15Raw signal. Nominal value is 3 vdc. Replace ECU and include value of V15Raw signal upon ECU return. Nominal V15 voltage is 3 vdc Bell 407 FADEC System Troubleshooting Guide Page 139 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File V5Flt 73-25-04-116 Hard Parent V5Flt Fault Description The ECU has detected a problem with an internal 5 volt dc power supply reference Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure See troubleshooting instructions for V5RgFlt child fault Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 140 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File V5RgFlt 73-25-04-116 Hard Child V5Flt Fault Description The ECU has detected a problem with an internal 5 volt dc power supply reference Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Fault Limits Special Limit Low High Open Circuit Reading 4.5 vdc 5.5 vdc N/A Troubleshooting Prodedure Record V5Raw signal. Replace ECU and include value of V5Raw signal upon ECU return. Bell 407 FADEC System Troubleshooting Guide Page 141 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File WDTFlt 73-25-04-116 Soft Parent N/A Fault Description The ECU has detected a problem with its watch dog timer during its self test Fault Test Conditions Continuous and transitions from manual into auto Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 142 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File WDTOutFlt 73-25-04-116 Soft Parent N/A Fault Description The ECU has detected that its watch dog timer has timed out once during software execution Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 143 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File WDTTimeOut 73-25-04-125 Hard Parent N/A Fault Description The ECU has detected that its watch dog timer has failed Fault Test Conditions Continuous Possible Fault Causes Internal ECU Failure Troubleshooting Prodedure Replace ECU Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 144 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File WfHdFlt 73-25-04-128 Hard Parent N/A Fault Description The ECU has detected that the HMU stepper is not moving or can not initialize its step count fuel flow Fault Test Conditions Continuous Possible Fault Causes See possible fault causes for StepCntFlt and WfmvFlt Troubleshooting Prodedure See troubleshooting instructions for StepCntFlt and WfmvFlt Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A WfHdFlt declared if a WfmvFlt exists on power up or during a switchover attempt from manual into automatic Bell 407 FADEC System Troubleshooting Guide Page 145 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File WfLimFlag 73-25-04-130 N/A Parent WfLimFlag Fault Description The ECU has detected that its fuel flow limiter was active for at least 2 seconds Fault Test Conditions Continuous when engine is in run mode Possible Fault Causes HMU internal contamination, kinked fuel delivery system supply lines, clogged CEFA filter, faulty in-range Wf feedback potentiometer signal Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Engine operating on fuel flow limiter for at least 2 seconds Troubleshooting Prodedure Monitor WfActual with engine operating at ground idle. Fuel flow should be approximately 100 pph at S.L. If WfActual is > 140 pph, replace HMU. If indications are normal, perform troubleshooting instructions for an WfmvFlt. Repair if required. Otherwise, after inspecting airframe fuel delivery for kinked hoses, clogged filters, etc., replace HMU. If contamination is found within the CEFA filter, replace HMU and purge fuel system lines. Bell 407 FADEC System Troubleshooting Guide Page 146 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File WfmvFlt 73-25-04-105 Soft Parent WfmvFlt Fault Description The ECU has detected a problem with its fuel flow feedback input from the HMU Wf potentiometer Fault Test Conditions Continuous Possible Fault Causes HMU feedback potentiometer intermittant failure, wiring intermittant between ECU and HMU Wf feedback potentiometer Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Troubleshooting Prodedure See troubleshooting instructions for either a WfmvRgFlt or WfmvRtFlt child fault Bell 407 FADEC System Troubleshooting Guide Page 147 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File WfmvRgFlt 73-25-04-105 Soft Child WfmvFlt Fault Description The ECU has detected a problem with its fuel flow feedback input from the HMU Wf potentiometer which has gone out of range Fault Test Conditions Continuous Possible Fault Causes HMU feedback potentiometer intermittant failure, wiring intermittant between ECU and HMU Wf feedback potentiometer Fault Limits Low High Open Circuit Reading -121.7 pph 568.0 pph WfmvRaw < -100 PPH Special Limit Troubleshooting Prodedure Monitor WfmvRaw after power up. Should be approximately -10 pph. Trend data while flexing harness. Analyze WfmvRaw data for signs of signal fallout or a wandering signal. Replace and repair wiring as required. If OK, replace HMU. Note: Never replace an ECU for this fault. Resistance checks of Wf potentiometer readings are at on fixed position (shutoff) only. This failure is most likely caused by the internal Wf potentiometer within the HMU but wiring problems have also caused this fault. Bell 407 FADEC System Troubleshooting Guide Page 148 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File WfmvRtFlt 73-25-04-105 Soft Child WfmvFlt Fault Description The ECU has detected a problem with its fuel flow feedback input from the HMU Wf potentiometer which has failed intermittantly Fault Test Conditions Continuous Possible Fault Causes HMU feedback potentiometer intermittant failure, wiring intermittant between ECU and HMU Wf feedback potentiometer Fault Limits Low High Open Circuit Reading -121.7 pph 568.0 pph WfmvRaw < -100 PPH Special Limit Troubleshooting Prodedure Monitor WfmvRaw after power up. Should be approximately -10 pph. Trend data while flexing harness. Analyze WfmvRaw data for signs of signal fallout or a wandering signal. Replace and repair wiring as required. If OK, replace HMU. Note: Never replace an ECU for this fault. Resistance checks of Wf potentiometer readings are at on fixed position (shutoff) only. This failure is most likely caused by the internal Wf potentiometer within the HMU but wiring problems have also caused this fault. Bell 407 FADEC System Troubleshooting Guide Page 149 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File WfStFlt 73-25-04-121 Hard Parent N/A Fault Description The ECU has detected that its step count fuel flow is not within range Fault Test Conditions Continuous when engine is in run mode Possible Fault Causes See possible fault causes for StepCntFlt and WfmvFlt Troubleshooting Prodedure See troubleshooting instructions for StepCntFlt and WfmvFlt Fault Limits Special Limit Low High Open Circuit Reading N/A N/A N/A Bell 407 FADEC System Troubleshooting Guide Page 150 of 150 Fault Name FIM Task Failure Type Fault Level Fault Test File WfStRgFlt 73-25-04-121 Hard Child N/A Fault Description The ECU has detected that its step count fuel flow is not within range Fault Test Conditions Continuous when engine is in run mode Possible Fault Causes See possible fault causes for StepCntFlt and WfmvFlt Troubleshooting Prodedure See troubleshooting instructions for StepCntFlt and WfmvFlt Fault Limits Special Limit Low High Open Circuit Reading -121.7 pph 568.0 pph N/A
