05/06/21
Message Overview:
Message Description:
Left engine N1 compensator fault.
[MCID 0507]
N1 Compensator 4.
Detection of a fault in the N1 compensator harness between the N1 compensator and both ECU A and ECU B.
Such that full system operation cannot be supported.
Possible Causes:
- N1 Compensator
- Full Authority Digital Engine Control Unit (FADEC) Electronic Control Unit A (ECU) (A41)
- Full Authority Digital Engine Control Unit (FADEC) Electronic Control Unit B (ECU) (A43)
- W6 Wiring Harness
Troubleshooting Tips:
Advisory Wire/Service Bulletin:
- AW300-36-0008 - "WING ANTI-ICE LEAK" EICAS Message During Climb
Forum Articles/Infoservice/Newsletter: None
Experience has shown that not turning the WAI OFF after a 'WING ANTI-ICE LEAK' CAS message could lead to an 'ENG THRUST FAULT' CAS message. Refer to the Advisory Wire listed above for more details.
When Batteries are 'ON' and engines are not running, if WAI is 'ON' while the rotary switch is on 'NORM', the L & R ENG THRUST FAULT CAS message will displayed.
Quick Links:
| General Visual Inspection of the Engine Wiring Harness | AMM 71-50-00-210-802 |
| Removal of the FADEC Electrical Harness from the Left Engine | AMM 71-50-05-000-802 |
| Installation of the FADEC Electrical Harness on the Left Engine | AMM 71-50-05-400-802 |
| Removal of the Engine Electronic Control Unit (ECU) | AMM 76-10-05-000-801 |
| Installation of the Engine Electronic Control Unit (ECU) | AMM 76-10-05-400-801 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
| Electrical Connectors - Maintenance Practice - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
- Interrogate the MDC as follows:
- On the cursor control panel, ensure the toggle switch is to the right and select Anti-Ice, ECS and Fuel buttons simultaneously. Press ENTER. The MDC main menu should now be displayed on Display Unit #3.
- Using the joystick, select Current Faults (if the fault is active) or Aircraft History to research stored faults. From Aircraft History you can then select 'Fault History' and locate the fault. Going into advanced diagnostics will provide an Equation ID for the fault identified.
- Select the MDC fault or Equation ID from the drop down below to get additional information to assist in troubleshooting.
- Check for the following MDC messages displayed with the fault:
- - X-channel bus 1A (MCID 0905),
- - X-channel bus 1B (MCID 0906),
- - X-channel discrete 1A (MCID 0933),
- - X-channel discrete 1B (MCID 0934).
- If any of the above MCID codes are posted, correct the cross channel faults first.
- If none of these fault codes are present, continue with next step.
- Troubleshoot using the following steps for aircraft and engine fault isolation with reference to the Light Engine Maintenance Manual TASK 72-00-00-810-076-A01.
- If MCID 0507 fault only is present, troubleshoot using the following steps for aircraft and engine fault isolation with reference to the Light Engine Maintenance Manual TASK 72-00-00-810-072.
- Reset and reboot the ECU to recheck the MDC MCID for the posted fault.
- Remove the connector on the N1 monopole W6P6, inspect for damaged pins/sockets, then check the following segments per the table, repair wiring if required per the wiring manual standard practices.
From To Value W6P6 Pin A W6P6 Pin B 2.5 to 15 kΩ W6P6 Pin C W6P6 Pin D 2.5 to 15 kΩ If good, check at the ECUs W6P3 Pin 25 W6P3 Pin 36 2.5 to 15 kΩ W6P2 Pin 25 W6P2 Pin 36 2.5 to 15 kΩ - If the resistance values fail at the N1 compensator, replace IAW Honeywell LEMM TASK 77-10-03-050-801. If the resistance values check good at the sensor and not at the ECU, suspect the W6 or W4 wiring harness, isolate by ringing individual wires and replace per the Honeywell LEMM TASK 76-10-01-050-801.
- If the wiring and compensator check good, consider swapping or replacing the A channel ECUs for the left engine, remove and replace IAW AMM TASK 76-10-05-000-801, TASK 76-10-05-400-801 then recheck the system for the fault.
