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(WARNING)
RED MESSAGE (CAUTION)
AMBER MESSAGE (ADVISORY)
CYAN MESSAGE (STATUS)
WHITE MESSAGE Require immediate crew attention. These messages are accompanied by flashing master warning, triple chime attenson with or without voice message or dedicated tone. Require immediate crew awareness and future crew action may be required in the form of alternate system selection or performance limitation. These message are accompanied by flashing master caution and a single chime. Indicate safe or normal system operation which require crew awareness, over and above the dark cockpit philosophy. Indicate minor failures or reduction in systems capability, which require no crew action.

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09/19/19

Message Overview:

Fault Message:

OPEN CKT - LCV/LCV RVDT PRIMARY WRG

Fault Code:

4960274APU

Associated CAS:

None

Reporting LRU: Full-Authority Digital Engine-Controller (FADEC)
System Description: 49-50-00
Schematic Diagram: 49-61-00 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wiring Diagram: 49-12-01 [ Global Express ]  [ G5000 ]  [ Global XRS ]
49-61-01 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Fault Description:

The Load Control Valve position-signals to the Full-Authority Digital Engine-Controller (FADEC) are lower than the usual values or higher than the usual values. This shows a possible open circuit in the Load Control Valve Rotary Variable-Differential Transformer (RVDT), the engine branched wiring-harness or the aircraft wiring harness.

Possible Causes:

  • Load Control Valve (LCV) (MPE1)
  • Auxiliary Power Unit (APU) Full-Authority Digital Engine-Controller (FADEC) (A108)
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

If CAS message is not active, verify stored faults on CAIMS.

Quick Links:

APU Safety Precautions AMM 49-00-00-910-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Engine Branched Wiring-Harness AMM 49-12-01-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Engine Branched Wiring-Harness AMM 49-12-01-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Load Control Valve AMM 49-52-05-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Load Control Valve AMM 49-52-05-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Full-Authority Digital Engine-Controller
(FADEC)		 AMM 49-61-01-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Full-Authority Digital Engine-Controller
(FADEC)		 AMM 49-61-01-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wire Repair - Maintenance Practices - ALL SPM 20-12-10-02 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Troubleshooting Recommendations:

  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, replace engine branched wiring-harness and do close out.
    2. If there is no bare wiring, kinks, worn areas or other damage, continue with next step.

  2. On the CAIMS PMAT, get access to the active faults.
  3. Check for any of the messages that follow shows on the CAIMS PMAT.

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

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

    1. If there is contamination or damage, go to step 26.
    2. If there is no contamination or damage, continue with next step.

  5. Check for any of the messages that follow shows on the CAIMS PMAT.

    • OPEN CKT - LCV/LCV RVDT PRIMARY WRG
    • OPEN CKT - LCV/LCV RVDT SEC VA WRG
    • OPEN CKT - LCV/LCV RVDT SEC VB WRG
    • SHORT CKT - LCV/LCV RVDT SEC VA WRG
    • SHORT CKT - LCV/LCV RVDT SEC VB WRG

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

  6. Perform a continuity check between the pins of load control valve (MPE1) receptacle (WM 49-12). The resistance should measure as follows:

    From To Expected Result Result
    MPE1P1-C MPE1P1-D 25-55 ohms

    1. If the resistance is not as mentioned above, go to step 26.
    2. If the resistance is as mentioned above, continue with next step.

  7. Check for any of the messages that follow show on the CAIMS PMAT.

    • OPEN CKT - LCV/LCV RVDT PRIMARY WRG
    • OPEN CKT - LCV/LCV RVDT SEC VA WRG
    • OPEN CKT - LCV/LCV RVDT SEC VB WRG
    • SHORT CKT - LCV/LCV RVDT SEC VA WRG
    • SHORT CKT - LCV/LCV RVDT SEC VB WRG

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

  8. Perform a continuity check between the pins of load control valve (MPE1) receptacle (WM 49-12). The resistance should measure as follows:

    From To Expected Result Result
    MPE1P1-E MPE1P1-G 30-50 ohms

    1. If the resistance is not as mentioned above, go to step 26.
    2. If the resistance is as mentioned above, continue with next step.

  9. Check for any of the messages that follow show on the CAIMS PMAT.

    • OPEN CKT - LCV/LCV RVDT PRIMARY WRG
    • OPEN CKT - LCV/LCV RVDT SEC VA WRG
    • OPEN CKT - LCV/LCV RVDT SEC VB WRG
    • SHORT CKT - LCV/LCV RVDT SEC VA WRG
    • SHORT CKT - LCV/LCV RVDT SEC VB WRG

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

  10. Perform a continuity check on the load control valve (MPE1) receptacle. The resistance should measure as follows:

    From To Expected Result Result
    MPE1P1-E MPE1P1-F 15-25 ohms
    MPE1P1-F MPE1P1-G 15-25 ohms

    1. If the resistance is not as mentioned above, go to step 26.
    2. If the resistance is as mentioned above, continue with next step.

  11. Check for any of the messages that follow show on the CAIMS PMAT.

    • OPEN CKT - LCV/LCV RVDT PRIMARY WRG
    • OPEN CKT - LCV/LCV RVDT SEC VA WRG
    • OPEN CKT - LCV/LCV RVDT SEC VB WRG
    • SHORT CKT - LCV/LCV RVDT SEC VA WRG
    • SHORT CKT - LCV/LCV RVDT SEC VB WRG

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

  12. Perform a check for insulation resistance between the load control valve (MPE1) and the ground shell. The resistance should measure as follows:

    From To Expected Result Result
    MPE1P1-E Ground Shell >1 megohm
    MPE1P1-F Ground Shell >1 megohm
    MPE1P1-G Ground Shell >1 megohm

    1. If the resistance is not as mentioned above, go to step 26.
    2. If the resistance is as mentioned above, continue with next step.

  13. Check for any of the messages that follow show on the CAIMS PMAT.

    • OPEN CKT - LCV/LCV RVDT PRIMARY WRG
    • OPEN CKT - LCV/LCV RVDT SEC VA WRG
    • OPEN CKT - LCV/LCV RVDT SEC VB WRG
    • SHORT CKT - LCV/LCV RVDT SEC VA WRG
    • SHORT CKT - LCV/LCV RVDT SEC VB WRG

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

  14. Perform wiring checks between APU (P1) and load control valve (MPE1P1).

    1. If wiring checks are not good, repair defective wiring as required and do close out.
    2. If wiring checks are good, continue with next step.

  15. Check for any of the messages that follow show on the CAIMS PMAT.

    • OPEN CKT - LCV/LCV RVDT PRIMARY WRG
    • OPEN CKT - LCV/LCV RVDT SEC VA WRG
    • OPEN CKT - LCV/LCV RVDT SEC VB WRG
    • SHORT CKT - LCV/LCV RVDT SEC VA WRG
    • SHORT CKT - LCV/LCV RVDT SEC VB WRG

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

  16. Perform a check for insulation resistance between each pin that follows and the ground shell (WM 49-12). The resistance should measure as follows:

    From To Expected Result Result
    P802-23 Ground Shell >1 megohm
    P802-24 Ground Shell >1 megohm
    P802-25 Ground Shell >1 megohm
    MPE1P1-E Ground Shell >1 megohm
    MPE1P1-F Ground Shell >1 megohm
    MPE1P1-G Ground Shell >1 megohm

    1. If the resistance is not as mentioned above, replace engine branched wiring-harness and do close out.
    2. If the resistance is as mentioned above, continue with next step.

  17. Check for any of the messages that follow show on the CAIMS PMAT.

    • OPEN CKT - LCV/LCV RVDT PRIMARY WRG
    • OPEN CKT - LCV/LCV RVDT SEC VA WRG
    • OPEN CKT - LCV/LCV RVDT SEC VB WRG
    • SHORT CKT - LCV/LCV RVDT SEC VA WRG
    • SHORT CKT - LCV/LCV RVDT SEC VB WRG

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

  18. Perform a check for insulation resistance on the P1 (P802) connector. The resistance should measure as follows:

    From To Expected Result Result
    P802-23 P802-24 >1 megohm
    P802-23 P802-25 >1 megohm
    P802-24 P802-25 >1 megohm

    1. If the resistance is not as mentioned above, replace engine branched wiring-harness and do close out.
    2. If the resistance is as mentioned above, continue with next step.

  19. Check for any of the messages that follow show on the CAIMS PMAT.

    • OPEN CKT - LCV/LCV RVDT PRIMARY WRG
    • OPEN CKT - LCV/LCV RVDT SEC VA WRG
    • OPEN CKT - LCV/LCV RVDT SEC VB WRG
    • SHORT CKT - LCV/LCV RVDT SEC VA WRG
    • SHORT CKT - LCV/LCV RVDT SEC VB WRG

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

  20. Perform wiring checks between aircraft wiring harness (J802) and FADEC (A108AP1).

    1. If wiring checks are not good, repair defective wiring as required and do close out.
    2. If wiring checks are good, continue with next step.

  21. Check for any of the messages that follow show on the CAIMS PMAT.

    • OPEN CKT - LCV/LCV RVDT PRIMARY WRG
    • OPEN CKT - LCV/LCV RVDT SEC VA WRG
    • OPEN CKT - LCV/LCV RVDT SEC VB WRG
    • SHORT CKT - LCV/LCV RVDT SEC VA WRG
    • SHORT CKT - LCV/LCV RVDT SEC VB WRG

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

  22. Perform a check for insulation resistance on the J802 connector. The resistance should measure as follows:

    From To Expected Result Result
    J802-23 J802-24 >1 megohm
    J802-23 J802-25 >1 megohm
    J802-24 J802-25 >1 megohm

    1. If the resistance is not as mentioned above, replace or repair defective wiring as required and do close out.
    2. If the resistance is as mentioned above, continue with next step.

  23. Check for any of the messages that follow show on the CAIMS PMAT.

    • OPEN CKT - LCV/LCV RVDT PRIMARY WRG
    • OPEN CKT - LCV/LCV RVDT SEC VA WRG
    • OPEN CKT - LCV/LCV RVDT SEC VB WRG
    • SHORT CKT - LCV/LCV RVDT SEC VA WRG
    • SHORT CKT - LCV/LCV RVDT SEC VB WRG

    1. If the messages are shown, troubleshoot the message first and continue with next step.
    2. If the messages are not shown, continue with next step.

  24. Perform a check for insulation resistance between each pin that follows and the ground shell (WM 49-61). The resistance should measure as follows:

    From To Expected Result Result
    J802-23 Ground Shell >1 megohm
    J802-24 Ground Shell >1 megohm
    J802-25 Ground Shell >1 megohm
    A108AP1-A9 Ground Shell >1 megohm
    A108AP1-B9 Ground Shell >1 megohm
    A108AP1-C9 Ground Shell >1 megohm

    1. If the resistance is not as mentioned above, replace or repair defective wiring as required and do close out.
    2. If the resistance is as mentioned above, continue with next step.

  25. Replace FADEC.

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

  26. Replace Load Control Valve (MPE1).
  27. Do close out.

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