Fault Message:

OPEN CKT- LCV/LCV TORQUE MOT WIRING

Fault Code:

4960213APU

Associated CAS:

None

The Load Control Valve Torque Motor signals from the Full-Authority Digital Engine-Controller (FADEC) are lower than the usual values. This shows a possible open circuit in the Load Control Valve Torque Motor, the engine branched wiring-harness or the aircraft wiring harness.

• Load Control Valve (MPE1)
• Full-Authority Digital Engine-Controller (FADEC) (A108)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

1. Examine the engine branched wiring-harness for bare wiring, kinks, worn areas and other damage (WM 49-12).

   1. If there is bare wiring, kinks, worn areas or other damage, go to step 10.
   2. If OPEN CKT-LCV/LCV TORQUE MOT WIRING still shows on CAIMS PMAT, continue with next step.

2. Examine the load control valve (MPE1) receptacle for contamination and damage.

   1. If there is contamination or damage, go to step 11.
   2. If OPEN CKT-LCV/LCV TORQUE MOT WIRING still shows on CAIMS PMAT, continue with next step.

3. Perform a continuity check on the load control valve connector (MPE1) receptacle (WM 49-12) as follows:

   From	To	Expected Result	Result
   MPE1P1-A	MPE1P1-B	65 - 85 ohms

   1. If resistance check fails, go to step 11.
   2. If OPEN CKT-LCV/LCV TORQUE MOT WIRING still shows on CAIMS PMAT, continue with next step.

4. Perform a insulation resistance check on load control valve (MPE1) as follows (WM 49-12):

   From	To	Expected Result	Result
   MPE1P1-A	Ground	>1 megohm
   MPE1P1-B	Ground	>1 megohm

   1. If resistance check fails, go to step 11.
   2. If OPEN CKT-LCV/LCV TORQUE MOT WIRING still shows on CAIMS PMAT, continue with next step.

5. Perform a insulation resistance check on APU connector (P802) as follows (WM 49-12):

   From	To	Expected Result	Result
   P802-21	P802-22	>1 megohm

   1. If resistance check fails, go to step 10.
   2. If OPEN CKT-LCV/LCV TORQUE MOT WIRING still shows on CAIMS PMAT, continue with next step.

6. Perform a insulation resistance check on APU connector (P802) as follows (WM 49-12):

   From	To	Expected Result	Result
   P802-21	Ground	>1 megohm
   P802-22	Ground	>1 megohm

   1. If resistance check fails, go to step 10.
   2. If OPEN CKT-LCV/LCV TORQUE MOT WIRING still shows on CAIMS PMAT, continue with next step.

7. Perform a insulation resistance check on FADEC connector (A108AP1) as follows (WM 49-61):

   From	To	Expected Result	Result
   A108AP1-J1	A108AP1-K1	>1 megohm

   1. If resistance check fails, repair defective wiring as required and do close out.
   2. If OPEN CKT-LCV/LCV TORQUE MOT WIRING still shows on CAIMS PMAT, continue with next step.

8. Perform a insulation resistance check between aircraft wiring harness connector (J802) and FADEC connector (A108AP1) as follows (WM 49-61):

   From	To	Expected Result	Result
   J802-21	Ground	>1 megohm
   J802-22	Ground	>1 megohm
   A108AP1-J1	Ground	>1 megohm
   A108AP1-K1	Ground	>1 megohm

1. If resistance check fails, repair defective wiring as required and do close out.
2. If checks are good, continue with next step.

9. Replace FADEC.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

10. Replace engine branched wiring-harness.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

11. Replace load control valve.
12. Do close out.