bell 407 fadec system troubleshooting guide page 1 of 150 cd/vih... · 2003-03-04 · bell 407...

Bell 407 FADEC System Troubleshooting Guide of 150

AD12BitFlt

The ECU has detected a problem with an internal chip responsible for converting input sensor analog data to digital data

Continuous

Internal ECU Failure

Hard

Fault Name

Possible Fault Causes

Failure Type

Fault Description

Fault Test Conditions

Parent

Fault Level

73-25-04-116

FIM Task

N/A

Special LimitFault Limits

Low High

N/A

Troubleshooting Prodedure

Replace ECU

Open Circuit Reading

N/A

Fault Test File

N/A


AD8BitFlt

The ECU has detected a problem with an internal chip responsible for converting input voltage and current data to digital data

Continuous


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Replace ECU


N/A

Fault Test File

N/A


AF28Flt

The ECU has detected that its power input from the aircraft dc bus was not within limits for at least 30 seconds

Continuous

Low airframe battery, FADEC circuit breaker pulled with engine running, high voltage from ground power source

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-117

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for AF28RgFlt child fault


N/A

Fault Test File

AF28Flt


AF28RgFlt

The ECU has detected that its power input from the aircraft dc bus was not within limits for at least 30 seconds

Continuous

Low airframe battery, FADEC circuit breaker pulled with engine running, high voltage from ground power source

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-117

FIM Task

8.5 vdc


Low High

35 vdc


Compare AF28Raw parameter against range limits at power up with both battery and ground power source. Also monitor during engine start for low voltage.


N/A

Fault Test File

AF28Flt


AL28Flt

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

Test enabled at N2 > 85%

Bad engine PMA or one phase of the alternator is open or shorted

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-111

FIM Task

8.5 vdc


Low High

60 vdc

ac ripple > 3 vac


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.


N/A

Fault Test File

AL28Flt


AMFlt

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

Continuous

Bad FADEC auto/manual select switch or wiring to the HMU auto/manual solenoid

Manual

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-128

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for either the AMSolFlt or AMSwFlt child faults


N/A

Fault Test File

N/A


AMIFlt

The ECU has detected a problem with the current flow from the HMU auto/manual solenoid

Continuous

Open circuit between ECU and HMU auto/manual solenoid

Manual

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-103

FIM Task

N/A


Low High

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


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.


N/A

Fault Test File

AMIFlt


AMSolFlt

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

Continuous

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

Manual

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-103

FIM Task

N/A


Low High

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


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.


N/A

Fault Test File

AMSolFlt


AMSwFlt

The ECU has detected a problem with the FADEC auto/manual mode selection switch

Continuous

Bad FADEC mode select switch or wiring from the switch to the ECU

Manual

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-119

FIM Task

N/A


Low High

N/A

Fault is declared if the ECU detects that neither mode is selected or if both modes are selected simultaneously


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.


N/A

Fault Test File

AMSwFlt


ARINCFltAn

This fault code not used in this application

ECU write to EEPROM or RAM interrupted during engine shutdown causing erroneous recording of an unused fault

Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-127

FIM Task

N/A


Low High

N/A


If fault is historical, clear all faults with the MT35 program. Cycle power and verify that fault is cleared.


N/A

Fault Test File

N/A


ARINCHWFlt



Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


BacCompFlt

The ECU has detected that it has not completed its background tasks within the allotted time period

Power up or during background tasks

Internal ECU Failure. Very unlikely to occur.

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Replace ECU


N/A

Fault Test File

N/A


CJCFlt

The ECU has detected a problem with its internal cold junction used to process its MGT input signal

Continuous

Internal ECU Failure.

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for either a CJCRgFlt or CJCRtFlt child fault


N/A

Fault Test File

CJCFlt


CJCRgFlt


Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

-80°F


Low High

250°F


Record CJCRaw signal. Replace ECU and include value of CJCRaw signal upon ECU return.


N/A

Fault Test File

CJCFlt


CJCRtFlt


Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

-80°F


Low High

250°F




N/A

Fault Test File

CJCFlt


CPAntFlt

The ECU has detected a problem with its collective pitch input used to maintain rotor rpm during aggressive flight maneuvers

Continuous

Airframe collective pitch potentiometer mis rigged or failed intermittently

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-113

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for CPRgFlt child fault


N/A

Fault Test File

CPFlt


CPDFlt



Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-127

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


CPFlt


Continuous


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-113

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for CPRgFlt child fault


N/A

Fault Test File

CPFlt


CPRgFlt


Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-113

FIM Task

-14.3%


Low High

110%


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.


CpRaw < -20%

Fault Test File

CPFlt


ECUOTFlt

The ECU has detected that its internal temperature, as measured by its cold junction, is extremely high

Continuous


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

230°F




N/A

Fault Test File

ECUOTFlt


EECalFlt

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

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Record KinP1Gn, KinP1Cal, KinQGn and KinQCal values. Replace ECU and include values upon ECU return


N/A

Fault Test File

EECalFlt


EEHistFlt

The ECU has detected that the engine history data in its memory may be corrupted

Continuous

ECU write to historical EEPROM interrupted during engine shutdown causing erroneous history data to be written in memory

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


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.


N/A

Fault Test File

N/A


EEPROMFlt

The ECU has detected a problem with internal calibration or engine historical data

Continuous

ECU write to historical EEPROM interrupted during engine shutdown causing erroneous history data to be written in memory

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


See troubleshooting for EECalFlt or EEHistFlt as appropriate


N/A

Fault Test File

N/A


ForCompFlt

The ECU has detected that it has not completed its forground tasks within the allotted time period

Continuous


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Replace ECU


N/A

Fault Test File

N/A


FTempFlt



Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-127

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


GainFlt

The ECU has detected a problem with a voltage reference used to process some of its input signals

Continuous


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for GainRgFlt child fault


N/A

Fault Test File

GainFlt


GainRgFlt


Continuous


Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

2738 cnts


Low High

3019 cnts


Record GainVin signal. Replace ECU and include value of GainVin signal upon ECU return.


N/A

Fault Test File

GainFlt


HardFlt

The ECU has detected that a hard fault has occurred. This is the parent fault for all hard faults.

Continuous

Determined by any sub-tier hard fault

Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-128

FIM Task

N/A


Low High

N/A


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.


N/A

Fault Test File

N/A


HLRfFlt


Continuous


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for HLRfRgFlt child fault


N/A

Fault Test File

HLRfFlt


HLRfRgFlt


Continuous


Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

3890 cnts


Low High

4077 cnts


Record HLRfRaw signal. Replace ECU and include value of HLRfRaw signal upon ECU return.


N/A

Fault Test File

HLRfFlt


IgnFlt

The ECU has detected a problem with its control of the airframe igniter relay during an auto mode start attempt

N1 between 50 and 60% during start or during auto-relight.

Open circuit between airframe igniter relay return and ECU or an ECU failure

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A

ECU detects an open circuit on the return wire from the igniter relay


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.


N/A

Fault Test File

IgnFlt


IgnIFlt

The ECU has detected a problem with its control of the airframe igniter relay prior to or during an auto mode start attempt

N1 between 50 and 60% during start or during auto-relight.

Faulty 1K3 FADEC Start Relay

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-120

FIM Task

N/A


Low High

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


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.


N/A

Fault Test File

IgnIFlt


LoadSelFlt

This fault code not used in this application and applies only to twin engine applications


Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-127

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


LoadSHdFlt



Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-127

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


MGTFlt

The ECU has detected a problem with its MGT input signal

Continuous

Loose or corroded connection at the MGT thermocouple junction on the engine

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-110

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for either a MGTRgFlt or MGTRtFlt child fault


N/A

Fault Test File

MGTFlt


MGTRgFlt

The ECU has detected a problem with its MGT input signal which has gone out of range

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-110

FIM Task

-77°F


Low High

2400°F


Monitor MGTRaw. If out of range high or low, check for open circuit between ECU and MGT thermocouple connection.


MGTRaw > 2400 °F

Fault Test File

MGTFlt


MGTRtFlt

The ECU has detected an intermittant problem with its MGT input signal

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-110

FIM Task

-77°F


Low High

2400°F


Monitor MGTRaw. If out of range high or low, check for open circuit between ECU and MGT thermocouple connection.


MGTRaw > 2400 °F

Fault Test File

MGTFlt


Ng12Flt

The ECU has detected a problem with both the Ng1 and Ng2 speed input signals or difference exists between both Ng inputs

Np > 45% OR either Ng1 or Ng2 is between 10 and 130%

Loose or corroded connection at the N1 speed sensor on the engine

Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-109

FIM Task

N/A


Low High

N/A

Ng1 and Ng2 differ by more than 5%


See troubleshooting instructions for Ng related child faults


N/A

Fault Test File

NgFlts


Ng1CyFlt

The ECU has detected a continuity problem with its Ng1 speed input signal

Continuous

Loose or corroded connection at the Ng1 speed sensor or a bad engine harness

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-109

FIM Task

8%


Low High

130%

Ng fault detection includes continuous continuity (trickle curret) testing


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.


Ng1CyBit = OPEN

Fault Test File

NgFlts


Ng1Flt

The ECU has detected a problem with its Ng1 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-109

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for Ng1 related child faults


N/A

Fault Test File

NgFlts


Ng1RgFlt

The ECU has detected an open, shorted or intermittent problem with its Ng1 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-109

FIM Task

8%


Low High

130%



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.


Ng1CyBit = OPEN

Fault Test File

NgFlts


Ng1RtFlt

The ECU has detected an intermittent problem with its Ng1 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-109

FIM Task

8%


Low High

130%





Ng1CyBit = OPEN

Fault Test File

NgFlts


Ng2CyFlt

The ECU has detected a continuity problem with its Ng2 speed input signal

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-109

FIM Task

8%


Low High

130%



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.


Ng1CyBit = OPEN

Fault Test File

NgFlts


Ng2Flt

The ECU has detected a problem with its Ng2 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-109

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for Ng2 related child faults


N/A

Fault Test File

NgFlts


Ng2RgFlt

The ECU has detected an open, shorted or intermittent problem with its Ng2 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-109

FIM Task

8%


Low High

130%





Ng2CyBit = OPEN

Fault Test File

NgFlts


Ng2RtFlt

The ECU has detected an intermittent problem with its Ng2 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-109

FIM Task

8%


Low High

130%





Ng2CyBit = OPEN

Fault Test File

NgFlts


NgDFlt

The ECU has detected that its Ng1 and Ng2 inputs do not agree within 5%

Ng1 or Ng2 > 13%

Loose or corroded connection at the Ng1 or Ng2 speed sensor output or a bad engine harness

Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-109

FIM Task

N/A


Low High

N/A

Ng1 and Ng2 differ by more than 5%


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.


N/A

Fault Test File

NgFlts


NgOFlt



Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-127

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


NgORgFlt



Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-127

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


NgORtFlt



Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-127

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


Np12Flt

The ECU has detected a problem with both the Np1 and Np2 speed input signals

Ng > 71% OR either Np1 or Np2 is between 45 and 160%

Loose or corroded connection at the N2 speed sensor on the engine

Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-108

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for Np related child faults


N/A

Fault Test File

NpFlts


Np1CyFlt

The ECU has detected a continuity problem with its Np1 speed input signal

Continuous

Loose or corroded connection at the Np1 speed sensor or a bad engine harness

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-108

FIM Task

20%


Low High

160%

Np fault detection includes continuous continuity (trickle curret) testing


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.


Np1CyBit = OPEN

Fault Test File

NpFlts


Np1Flt

The ECU has detected a problem with its Np1 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-108

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for Np1 related child faults


N/A

Fault Test File

NpFlts


Np1RgFlt

The ECU has detected an open, shorted or intermittent problem with its Np1 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-108

FIM Task

20%


Low High

160%



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.


Np1CyBit = OPEN

Fault Test File

NpFlts


Np1RtFlt

The ECU has detected an intermittent problem with its Np1 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-108

FIM Task

20%


Low High

160%





Np1CyBit = OPEN

Fault Test File

NpFlts


Np2CyFlt

The ECU has detected a continuity problem with its Np2 speed input signal

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-108

FIM Task

20%


Low High

160%



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.


Np1CyBit = OPEN

Fault Test File

NpFlts


Np2Flt

The ECU has detected a problem with its Np2 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-108

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for Np2 related child faults


N/A

Fault Test File

NpFlts


Np2RgFlt

The ECU has detected an open, shorted or intermittent problem with its Np2 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-108

FIM Task

20%


Low High

160%





Np2CyBit = OPEN

Fault Test File

NpFlts


Np2RtFlt

The ECU has detected an intermittent problem with its Np2 speed input signal



Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-108

FIM Task

20%


Low High

160%





Np2CyBit = OPEN

Fault Test File

NpFlts


NpDFlt

The ECU has detected that its Np1 and Np2 inputs do not agree within 5%


Loose or corroded connection at the Np1 or Np2 speed sensor output or a bad engine harness

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-108

FIM Task

N/A


Low High

N/A

Np1 and Np2 differ by more than 5%


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.


N/A

Fault Test File

NpFlts


NpOSFlt

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

Test active at Np > 55% or during overspeed system shutdown test

ECU internal failure. May be caused by an Np1Flt or Np2Flt so correcting the Np faults will fix the NpOSFlt

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-124

FIM Task

N/A


Low High

N/A

Np speed from frequency to voltage conversion within ECU does not agree with actual Np within 2.5%


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.


N/A

Fault Test File

NpOSFlt


NpQExLmAdv

The ECU has detected an Np maximum limit exceedance > 113.3% for 1 second

Continuous when in run mode

Overspeed while controlling engine in manual mode, selection of manual mode on the ground with throttle in flight position

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-129

FIM Task

N/A


Low High

N/A


Record NpQNppkExLm and NpQQpkExLm from ECU engine history. Perform engine maintenance as required.


N/A

Fault Test File

N/A


NpQRnLmAdv

The ECU has detected an Np maximum run limit exceedance > 102.1% for 15s

Continuous when in run mode


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-129

FIM Task

N/A


Low High

N/A


Record NpQNppkRnLm and NpQQpkRnLm from ECU engine history. Perform engine maintenance as required.


N/A

Fault Test File

N/A


NrAntDsb



Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-114

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


NrCyFlt

The ECU has detected a continuity problem with its Nr speed input signal

Continuous

Loose or corroded connection at the Nr speed sensor or a bad airframe harness

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-114

FIM Task

N/A


Low High

N/A

Nr fault detection includes continuous continuity (trickle curret) testing


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.


N/A

Fault Test File

NrFlt


NrDFlt



Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-127

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


NrFlt

The ECU has detected a problem with its Nr speed input signal

Ng > 71% OR either Np1 or Np2 is between 45 and 160% and engine not in test cell


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-114

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for NrCyFlt or NrRgFlt child faults


N/A

Fault Test File

NrFlt


NrRgFlt

The ECU has detected an open, shorted or intermittent problem with its Nr speed input signal



Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-114

FIM Task

40%


Low High

150%



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.


NrCyBit = OPEN

Fault Test File

NrFlt


NrRtFlt

The ECU has detected an intermittent problem with its Nr speed input signal



Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-114

FIM Task

40%


Low High

150%



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.


NrCyBit = OPEN

Fault Test File

NrFlt


OffsFlt


Continuous


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for OffsRgFlt child fault


N/A

Fault Test File

OffsFlt


OffsRgFlt


Continuous


Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

169 cnts


Low High

872 cnts


Record OffsRaw signal. Replace ECU and include value of OffsRaw signal upon ECU return.


N/A

Fault Test File

OffsFlt


OpenMvFlg

The ECU has detected that the HMU manual mode pistons are not properly parked

Test conducted at Ng < 8% while in start mode or shutdown

Engine last shutdown while in manual mode, airframe power turned off prematurely prior to a complete N1 coastdown

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-122

FIM Task

N/A


Low High

N/A

WfSel > 16 pph prior to start


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


N/A

Fault Test File

N/A


Or28Flt

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.

Continuous

Low airframe battery voltage upon power up.

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-128

FIM Task

N/A


Low High

N/A

Fault declared if voltage is out of range for at least 30 seconds


See troubleshooting instructions for Or28RgFlt child fault


N/A

Fault Test File

Or28Flt


Or28RgFlt

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.

Continuous

Low airframe battery voltage upon power up.

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-128

FIM Task

7.5 vdc


Low High

60 vdc

Fault declared if voltage is out of range for at least 30 seconds


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


N/A

Fault Test File

Or28Flt


OrDiodeFlt

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.

Continuous

High airframe voltage upon power up due to improperly adjusted power cart, high voltage output of engine PMA

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


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.


N/A

Fault Test File

OrDiodeFlt


OSFlag

The ECU has detected that an Np overspeed has occurred whereby the HMU overspeed valve was energized to limit the Np speed

OSFlag declared if overspeed valve is energized while Np > 106%


N/A

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-129

FIM Task

N/A


Low High

N/A


Record NpQ exceedance values and OSCtr from ECU engine history. Perform engine maintenance as required.


N/A

Fault Test File

N/A


OSFlt

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 declared due to either a NPOSFlt, failure of the overspeed system shutdown or power up tests

See troubleshooting for NPOSFlt or other OS related child faults

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-128

FIM Task

N/A


Low High

N/A


See troubleshooting for NPOSFlt or other OS related child faults


N/A

Fault Test File

OSFlt


OSI12Flt

The ECU has detected a failure in the current flow from the HMU overspeed solenoid valve

Test conducted during overspeed system shutdown live test or upon power up with throttle off

Open circuit between HMU overspeed valve and ECU, or an ECU failure

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-104

FIM Task

N/A


Low High

N/A

Fault declared if solenoid current flow > 3 amps when HMU overspeed solenoid valve is on


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.


N/A

Fault Test File

OSI12Flt


OSTst1Flt

The ECU has detected a failure in its ability to control the HMU overspeed solenoid valve during its power up test

Test conducted during power up with throttle off in auto mode

Open/short circuit between HMU overspeed valve and ECU, or an ECU failure

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-104

FIM Task

N/A


Low High

N/A


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.


N/A

Fault Test File

OSFlt


OSTst2Flt




Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-104

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

OSFlt


OSTst3Flt




Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-104

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

OSFlt


OSTst4Flt




Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-104

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

OSFlt


OSTst5Flt




Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-104

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

OSFlt


OSTst6Flt




Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-104

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

OSFlt


OSTst7Flt




Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-104

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

OSFlt


OSTstFlt

The ECU has detected a failure of the HMU during an overspeed system shutdown test

Test conducted during aircraft overspeed system shutdown test

HMU failure or test conducted at high altitude.

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-123

FIM Task

N/A


Low High

N/A

Fault declared if N1 speed does not decrease by more that 1% when HMU solenoid valve is energized


Replace HMU or repeat overspeed system shutdown test at a lower altitude.


N/A

Fault Test File

OSFlt


OSTstSwFlt

The ECU has detected a failure of the cockpit overspeed test switch

Continuous

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.

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-118

FIM Task

N/A


Low High

N/A

Fault declared if cockpit test switch closed for more that 30 sec


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.


N/A

Fault Test File

OSTstSwFlt


OSVFlt

The ECU has detected a problem with a voltage reference used within its overspeed protection circuitry

Continuous


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for OSVRgFlt child fault


N/A

Fault Test File

OSVFlt


OSVRgFlt

The ECU has detected a problem with a voltage reference used within its overspeed protection circuitry

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

4.5 vdc


Low High

6.0 vdc


Record OSVRaw signal. Replace ECU and include value of OSVRaw signal upon ECU return.


N/A

Fault Test File

OSVFlt


P1DFlt



Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

73-25-04-127

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


P1Flt

The ECU has detected a failure of its internal P1 ambient pressure transducer

Continuous


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-115

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for P1RgFlt or P1RtFlt child faults


N/A

Fault Test File

P1Flt


P1HdFlt

The ECU has detected a failure of its internal P1 ambient pressure transducer and can not calculate a syntesized P1 to accommodate the failure

Continuous

Internal ECU Failure and a Q failure

Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-115

FIM Task

N/A


Low High

N/A


Record P1Raw signal. Replace ECU and include value of P1Raw signal upon ECU return.


N/A

Fault Test File

P1Flt


P1RgFlt

The ECU has detected a failure of its internal P1 ambient pressure transducer where its P1 signal was out of range

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-115

FIM Task

5 psia


Low High

16 psia




N/A

Fault Test File

P1Flt


P1RtFlt

The ECU has detected a failure of its internal P1 ambient pressure transducer where its P1 signal failed at a high rate of change

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-115

FIM Task

5 psia


Low High

16 psia




N/A

Fault Test File

P1Flt


PLA12Flt

The ECU has detected that both throttle inputs have failed or that they do not agree within 5 degrees

Continuous

HMU PLA potentiometer failure or throttle min/max stops on HMU quadrant shifted during initial HMU installation

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-106

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for PLA1RgFlt or PLA2RgFlt child faults


N/A

Fault Test File

PLAFlts


PLA1Flt

The ECU has detected that its PLA1 input has failed

Continuous


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-106

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for PLA1RgFlt


N/A

Fault Test File

PLAFlts


PLA1RgFlt

The ECU has detected that its PLA1 input has failed out of range

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-106

FIM Task

-5 deg


Low High

110 deg


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.


PLA1Raw > 120°

Fault Test File

PLAFlts


PLA2Flt

The ECU has detected that its PLA2 input has failed

Continuous


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-106

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for PLA1RgFlt


N/A

Fault Test File

PLAFlts


PLA2RgFlt

The ECU has detected that its PLA2 input has failed out of range

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-106

FIM Task

-5 deg


Low High

110 deg




PLA2Raw > 120°

Fault Test File

PLAFlts


PLADFlt

The ECU has detected that both throttle inputs do not agree within 5 degrees

Continuous

ECU failure or wiring problem between ECU and HMU PLA potentiometer

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-106

FIM Task

N/A


Low High

N/A

Fault declared if PLA1 and PLA2 are not within 5 degrees of eachother


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.


N/A

Fault Test File

PLAFlts


PLAHdFlt

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

Continuous


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-106

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

PLAFlts


PLARfFlt

The ECU has detected that the voltage supply reference to the HMU PLA potentiometer has failed

Continuous

ECU Failure or shorted wiring between ECU and HMU PLA potentiometer

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-106

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for PLARfRgFlt child fault


N/A

Fault Test File

PLAFlts


PLARfRgFlt

The ECU has detected that the voltage supply reference to the HMU PLA potentiometer has failed out of range

Continuous

ECU Failure or shorted wiring between ECU and HMU PLA potentiometer

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-106

FIM Task

4.95 vdc


Low High

5.05 vdc


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.


N/A

Fault Test File

PLAFlts


PROMFlt

The ECU has detected that its program checksum does not agree with the value stored at the factory

Power up and background tasks


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Record value of ID on the MT35 program header and return ECU with ID value. The ID value should be 443F.


N/A

Fault Test File

N/A


PW10Flt

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

Continuous


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for PW10RgFlt child fault


N/A

Fault Test File

PW10Flts


PW10RgFlt

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

Continuous


Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

6.5 vdc


Low High

11 vdc


Record value of PW10Raw signal and return ECU with PW10Raw value


N/A

Fault Test File

PW10Flts


QFlt

The ECU has detected a problem with its torque input signal or has determined the torque input is invalid

Continuous

Loose or corroded connection at the TMOP sensor on the engine, oil in TMOP sensor connection, bad TMOP sensor

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-112

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for either a QRgFlt or QRtFlt child fault


N/A

Fault Test File

QFlt


QRgFlt

The ECU has detected a problem with its torque input signal which has gone out of range

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-112

FIM Task

-10%


Low High

200%

Low limit of 5% if N1 > 85% under steady state conditions


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.


QRaw > 200%

Fault Test File

QFlt


QRtFlt

The ECU has detected an intermittant problem with its torque input signal

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-112

FIM Task

-10%


Low High

200%

Low limit of 5% if N1 > 85% under steady state conditions


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.


Qraw > 200%

Fault Test File

QFlt


QSwFlt

The ECU has detected a problem with the FADEC Quiet Mode switch (Optional)

Continuous

Bad FADEC quiet mode select switch or wiring from the switch to the ECU. Corrosion/moisture in airframe harness.

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-156

FIM Task

N/A


Low High

N/A

Fault is declared if the ECU detects that both quiet mode switch inputs do not agree.


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.


N/A

Fault Test File

QMSwFlt


QVldFlt

The ECU has determined that its torque input signal is invalid when it is compared to theoretical engine shaft horsepower determined from N1 speed

Continuous

Air trapped in TMOP sensor supply tube from the engine gearbox, bad TMOP sensor or erroneous P1 or T1 input to the DECU

Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-112

FIM Task

N/A


Low High

N/A

Np times Q times 0.06 > estimated engine horsepower as a function of N1 corrected speed


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.


N/A

Fault Test File

QVldFlt


RAMFlt

The ECU has detected a problem with its internal Random Access Memory (RAM)

Power up and background tasks


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Replace ECU


N/A

Fault Test File

N/A


SgFlag

The ECU has detected that the engine has surged

Continuous when in engine run mode

Inefficient engine compressor or faulty bleed band actuator

Soft

Fault Name


Failure Type

Fault Description


N/A

Fault Level

See AMM

FIM Task

N/A


Low High

N/A


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


N/A

Fault Test File

N/A


SMFlt

The ECU has detected a problem with its control of the HMU stepper motor

Power up test only with throttle off

Wiring problem between ECU and HMU stepper motor

Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-101

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for SmPhAVFlt, SmPhBVFlt, SmPhCVFlt, SmPhDVFlt or SmPhIFlt child faults


N/A

Fault Test File

SMFlt


SMPhAVFlt

The ECU has detected a problem with the control of phase A of the HMU stepper motor


Wiring problem between ECU and HMU stepper motor phase A return. Internal ECU phase A driver failure.

Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-101

FIM Task

N/A


Low High

N/A


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.


N/A

Fault Test File

SMFlt


SMPhBVFlt

The ECU has detected a problem with the control of phase B of the HMU stepper motor


Wiring problem between ECU and HMU stepper motor phase B return. Internal ECU phase B driver failure.

Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-101

FIM Task

N/A


Low High

N/A


Follow troubleshooting instructions for SmPhAVFlt referencing SmPhBVbit


N/A

Fault Test File

SMFlt


SMPhCVFlt

The ECU has detected a problem with the control of phase C of the HMU stepper motor


Wiring problem between ECU and HMU stepper motor phase C return. Internal ECU phase C driver failure.

Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-101

FIM Task

N/A


Low High

N/A


Follow troubleshooting instructions for SmPhAVFlt referencing SmPhCVbit


N/A

Fault Test File

SMFlt


SMPhDVFlt

The ECU has detected a problem with the control of phase D of the HMU stepper motor


Wiring problem between ECU and HMU stepper motor phase D return. Internal ECU phase D driver failure.

Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-101

FIM Task

N/A


Low High

N/A


Follow troubleshooting instructions for SmPhAVFlt referencing SmPhDVbit


N/A

Fault Test File

SMFlt


SMPhIFlt

The ECU has detected a problem with current flow from on of the HMU stepper motor phases


Wiring problem between ECU and HMU stepper motor.

Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-101

FIM Task

N/A


Low High

N/A

SmIBitRaw not between 0.1 amp and 1.5 amp when phase turned on. SmIBitRaw > 0.2 amp when phase supposedly off.


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.


N/A

Fault Test File

SMFlt


StepCntFlt

The ECU has detected that the HMU stepper is not moving when commanded to move

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.

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

Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-121

FIM Task

N/A


Low High

N/A

Difference between WfmvRaw fuel flow and Wfstp stepcount fuel flow greater than 42 PPH


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.


N/A

Fault Test File

StepCntFlt


StrFlt

The ECU has detected a problem with its control of the airframe starter relay during an auto mode start attempt

Start switch pressed in auto mode during start or auto-relight

Open circuit between airframe starter relay return and ECU or an ECU failure

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A

ECU detects an open circuit on the return wire from the starter relay


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.


N/A

Fault Test File

StrFlt


StSFlt

The ECU has detected a problem with its control of the HMU start fuel solenoid

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

Grounded wire between ECU and return from HMU start fuel solenoid

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-102

FIM Task

N/A


Low High

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


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.


N/A

Fault Test File

StSFlt


StSIFlt

The ECU has detected a problem with the current flow from the HMU start fuel solenoid

In auto mode, StSIbitRaw current not between 0.05 amp and 1.0 amp when HMU start fuel solenoid energized

Grounded or open wire between ECU and return from HMU start fuel solenoid

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-102

FIM Task

N/A


Low High

N/A

In auto mode, StSIbitRaw current not between 0.05 amp and 1.0 amp when HMU start fuel solenoid energized


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.


N/A

Fault Test File

StSFlt


SWIntFlt

The ECU has detected that abnormal software interrupts have occurred

Continuous


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Replace ECU


N/A

Fault Test File

N/A


T1ABFlt

The ECU has detected that both T1 ambient temperature inputs have failed or that they do not agree within 30°F

Continuous

Engine T1 sensor connection loose or corroded, T1 sensor failure

Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-107

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for T1ARgFlt, T1ARtFlt, T1BRgFlt and T1BRtFlt child faults


N/A

Fault Test File

T1Flts


T1AFlt

The ECU has detected a failure in its T1A ambient temperature input

Continuous

Engine T1A sensor output wiring loose or corroded

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-107

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for T1ARgFlt and T1ARtFlt child faults


N/A

Fault Test File

T1Flts


T1ARgFlt

The ECU has detected a failure in its T1A ambient temperature input which has gone out of range

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-107

FIM Task

-75°F


Low High

225°F

Difference between T1ARaw and T1BRaw > 30°F


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.


T1ARaw < -90 °F

Fault Test File

T1Flts


T1ARtFlt

The ECU has detected a failure in its T1A ambient temperature input which was intermittant

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-107

FIM Task

-75°F


Low High

225°F



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.


T1ARaw < -90 °F

Fault Test File

T1Flts


T1BFlt

The ECU has detected a failure in its T1B ambient temperature input

Continuous

Engine T1B sensor output wiring loose or corroded

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-107

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for T1BRgFlt and T1BRtFlt child faults


N/A

Fault Test File

T1Flts


T1BRgFlt

The ECU has detected a failure in its T1B ambient temperature input which has gone out of range

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-107

FIM Task

-75°F


Low High

225°F



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.


T1BRaw < -90 °F

Fault Test File

T1Flts


T1BRtFlt

The ECU has detected a failure in its T1B ambient temperature input which was intermittant

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-107

FIM Task

-75°F


Low High

225°F



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.


T1BRaw < -90 °F

Fault Test File

T1Flts


T1DFlt

The ECU has detected that both T1 ambient temperature inputs do not agree within 30°F

Continuous

Engine T1 sensor connection loose or corroded, T1 sensor failure

Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-107

FIM Task

N/A


Low High

N/A



See troubleshooting instructions for T1ARgFlt, T1ARtFlt, T1BRgFlt and T1BRtFlt child faults


N/A

Fault Test File

T1Flts


TempFlt

The ECU has detected a problem with its MGT input signal or its internal cold junction used to compensate the MGT input

Continuous

Loose or corroded connection at the MGT thermocouple junction on the engine or internal ECU failure

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-128

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for either a MGTFlt or CJCFlt child fault. TempFlt name only viewable with MT35 maintenance software


N/A

Fault Test File

N/A


TestCelFlt

The ECU has detected that its test cell input is grounded but it is still getting a rotor speed input

Test for grounded Testcell input when Nr > 50%

Erroneous ground on ECU TestCell Input

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-126

FIM Task

N/A


Low High

N/A


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.


N/A

Fault Test File

TestCelFlt


UARTFlt

The ECU has detected a problem with its RS-423 interface during its power up self test and/or background tests

Power up or during background tasks


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Replace ECU


N/A

Fault Test File

N/A


UUIntFlt

The ECU has detected that a software interrupt occurred from one which has not been assigned by the software

Continuous


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Replace ECU


N/A

Fault Test File

N/A


V15Flt

The ECU has detected a problem with an internal 15 volt dc power supply reference

Continuous


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for V15RgFlt child fault


N/A

Fault Test File

V15Flt


V15RgFlt


Continuous


Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

2.4 vdc


Low High

3.6 vdc

Nominal V15 voltage is 3 vdc


Record V15Raw signal. Nominal value is 3 vdc. Replace ECU and include value of V15Raw signal upon ECU return.


N/A

Fault Test File

V15Flt


V5Flt


Continuous


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for V5RgFlt child fault


N/A

Fault Test File

V5Flt


V5RgFlt


Continuous


Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-116

FIM Task

4.5 vdc


Low High

5.5 vdc


Record V5Raw signal. Replace ECU and include value of V5Raw signal upon ECU return.


N/A

Fault Test File

V5Flt


WDTFlt

The ECU has detected a problem with its watch dog timer during its self test

Continuous and transitions from manual into auto


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Replace ECU


N/A

Fault Test File

N/A


WDTOutFlt

The ECU has detected that its watch dog timer has timed out once during software execution

Continuous


Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-116

FIM Task

N/A


Low High

N/A


Replace ECU


N/A

Fault Test File

N/A


WDTTimeOut

The ECU has detected that its watch dog timer has failed

Continuous


Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-125

FIM Task

N/A


Low High

N/A


Replace ECU


N/A

Fault Test File

N/A


WfHdFlt

The ECU has detected that the HMU stepper is not moving or can not initialize its step count fuel flow

Continuous

See possible fault causes for StepCntFlt and WfmvFlt

Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-128

FIM Task

N/A


Low High

N/A

WfHdFlt declared if a WfmvFlt exists on power up or during a switchover attempt from manual into automatic


See troubleshooting instructions for StepCntFlt and WfmvFlt


N/A

Fault Test File

N/A


WfLimFlag

The ECU has detected that its fuel flow limiter was active for at least 2 seconds

Continuous when engine is in run mode

HMU internal contamination, kinked fuel delivery system supply lines, clogged CEFA filter, faulty in-range Wf feedback potentiometer signal

N/A

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-130

FIM Task

N/A


Low High

N/A

Engine operating on fuel flow limiter for at least 2 seconds


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.


N/A

Fault Test File

WfLimFlag


WfmvFlt

The ECU has detected a problem with its fuel flow feedback input from the HMU Wf potentiometer

Continuous

HMU feedback potentiometer intermittant failure, wiring intermittant between ECU and HMU Wf feedback potentiometer

Soft

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-105

FIM Task

N/A


Low High

N/A


See troubleshooting instructions for either a WfmvRgFlt or WfmvRtFlt child fault


N/A

Fault Test File

WfmvFlt


WfmvRgFlt

The ECU has detected a problem with its fuel flow feedback input from the HMU Wf potentiometer which has gone out of range

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-105

FIM Task

-121.7 pph


Low High

568.0 pph


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.


WfmvRaw < -100 PPH

Fault Test File

WfmvFlt


WfmvRtFlt

The ECU has detected a problem with its fuel flow feedback input from the HMU Wf potentiometer which has failed intermittantly

Continuous


Soft

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-105

FIM Task

-121.7 pph


Low High

568.0 pph


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.


WfmvRaw < -100 PPH

Fault Test File

WfmvFlt


WfStFlt

The ECU has detected that its step count fuel flow is not within range



Hard

Fault Name


Failure Type

Fault Description


Parent

Fault Level

73-25-04-121

FIM Task

N/A


Low High

N/A




N/A

Fault Test File

N/A


WfStRgFlt

The ECU has detected that its step count fuel flow is not within range



Hard

Fault Name


Failure Type

Fault Description


Child

Fault Level

73-25-04-121

FIM Task

-121.7 pph


Low High

568.0 pph




N/A

Fault Test File

N/A

bell 407 fadec system troubleshooting guide page 1 of 150 cd/vih... · 2003-03-04 · bell 407...

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