Fault Message:

LH WING XFER SOV/WRG

Fault Code:

284462CPK

Associated CAS:

-> FUEL XFER FAIL
(Caution)

-> FUEL XFER ON
(Caution)

L XFER VALVE OPEN
(Advisory)

L WING XFR VALVE/WRG FAULT shows on the CAIMS PMAT when the conditions that follow occur:

• The WING XFER Switch on the FUEL Control Panel is set to ⇒ with one of the Engines on
• The Left Wing-Transfer Shut-Off Valve indication is closed
• The Electrical Management System (EMS)/Secondary Power Distribution Assembly (SPDA) has not failed

or

• The WING XFER Switch is set to AUTO with the Left to Right Transfer command on
• The Left Wing-Transfer Shutoff-Valve indication is closed
• The EMS/SPDA has not failed

or

• The WING XFER Switch on the FUEL Control Panel is set to OFF or ⇐ with one of the Engines on
• The Left Wing-Transfer Shut-off Valve indication is open
• The EMS/SPDA has not failed

or

• The WING XFER Switch is set to AUTO with the left to right transfer command off
• The Left Wing-Transfer Shutoff-Valve indication is open
• The EMS/SPDA has not failed

• Left Cross Flow Shut-off Valve (L21)
• FUEL Control Panel (AP5)
• Wing Transfer Shut-off Valve Actuator
• Fuel Management and Quantity Gauging Computer (FMQGC) (A47)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

1. Activate the LEFT TO RIGHT WING TRANSFER page on the CAIMS PMAT display as follows:

   1. Set the WING XFER switch on the FUEL control panel to AUTO
   2. Access the system diagnostics on the CAIMS PMAT
   3. Select ATA 28-00 FUEL
   4. Select FMQGC CH A
   5. Select LRU TEST
   6. Select LEFT TO RIGHT WING TRANSFER
   7. Select OPEN LEFT TO RIGHT WING TRANSFER VALVE

2. Check if the indications that follow show on the LEFT TO RIGHT WING TRANSFER page:

   Reference	Indication
   VALVE OPEN POSITION SWITCH	Open
   VALVE CLOSED POSITION SWITCH	Closed
   VALVE OPEN POSITION SWITCH	Not Open
   VALVE CLOSED POSITION SWITCH	Not Closed

   1. If the results are not as described in the table above, go to step 5.
   2. If the results are as described in the table above, continue with the next step.

3. Disconnect the connector L21P1 from the LEFT CROSSFLOW SOV. Check if there is an open and a short-circuit to ground as follows:

   From	To	Expected Result	Result
   L21P1-F	Ground	Open
   L21P1-G	Ground	Continuity

   1. If the results are not as described in the table above, got to step 30.
   2. If the results are as described in the table above, continue with the next step.

4. Disconnect the connector A47AP1 from FMQGC. Check if there is an open and a short-circuit to ground as follows:

   From	To	Expected Result	Result
   A47AP1-K13	Ground	Open
   A47AP1-J13	Ground	Continuity

   1. If the results are as described in the table above, go to step 32.
   2. If the results are not as described in the table above, repair or replace the defective wiring as required and do close out.

5. Check if the indications that follow show on the LEFT TO RIGHT WING TRANSFER page:

   Reference	Indication
   VALVE OPEN POSITION SWITCH	Not Open
   VALVE CLOSED POSITION SWITCH	Closed

   1. If the results are not as described in the table above, go to step 13.
   2. If the results are as described in the table above, continue with the next step.

6. Disconnect the connector L21P1 from the LEFT CROSSFLOW SOV. Check for voltage as follows:

   LEFT CROSSFLOW SOV	Expected Result	Result
   L21P1-D	28 ±2 VDC
   L21P1-B	0 VDC

   1. If the results are as described in the table above, go to step 30.
   2. If the results are not as described in the table above, continue with the next step.

7. Disconnect the connector A14P4 from SPDA 2. Check for voltage as follows:

   SPDA 2	Expected Result	Result
   A14P4-A	28 ±2 VDC
   A14P4-E	0 VDC

   1. If the results are as described in the table above, repair or replace the defective wiring as required and do close out.
   2. If the results are not as described in the table above, continue with the next step.

8. Disconnect the connectors A91P1 from EMS CDU 2 and A94P1 from EMS CDU 1. Perform a continuity check as follows:

   From	To	Result
   A91P1-43	Ground
   A94P1-43	Ground

   1. If there is no continuity, perform a troubleshooting for the EMS CDUs or the SPDA 2 and do close out.
   2. If there is continuity, continue with the next step.

9. Disconnect connector A47AP1 from FMQGC. Perform a continuity check as follows:

   From	To	Result
   A47AP1-J12	Ground

   1. If there is continuity, go to step 32.
   2. If there is no continuity, continue with the next step.

10. Disconnect the connector AP5P1 from FUEL PANEL. Perform a continuity check as follows:

    From	To	Result
    AP5P1-35	Ground

    1. If there is continuity, repair or replace the defective wiring as required and do close out.
    2. If there is no continuity, continue with the next step.

11. Disconnect the connectors AP5P1 and AP5P2 from the FUEL PANEL, A91P1 from the EMS CDU 2 and A94P1 from the EMS CDU 1. Perform a continuity check as follows:

    From	To	Result
    AP5P1-28	A94P1-43
    AP5P2-28	A91P1-43

    1. If there is no continuity, repair or replace the defective associated wiring and do close out.
    2. If there is continuity, continue with the next step.

12. Perform a continuity check as follows:

    From	To	Result
    AP5P1-28	Ground
    AP5P2-28	Ground

    1. If there is continuity, repair or replace the defective wiring as required and do close out.
    2. If there is no continuity, go to step 31.

13. Select CLOSE LEFT TO RIGHT WING TRANSFER VALVE from the LEFT TO RIGHT WING TRANSFER page on the CAIMS PMAT. Check if the indications that follow show on the LEFT TO RIGHT WING TRANSFER page:

    Reference	Indication
    VALVE OPEN POSITION SWITCH	Open
    VALVE CLOSED POSITION SWITCH	Closed
    VALVE OPEN POSITION SWITCH	Not Open
    VALVE CLOSED POSITION SWITCH	Not Closed

    1. If the results are not as described in the table above, go to step 16.
    2. If the results are as described in the table above, continue with the next step.

14. Disconnect the connector L21P1 from the LEFT CROSSFLOW SOV. Check if there is an open and a short-circuit to ground as follows:

    From	To	Expected Result	Result
    L21P1-G	Ground	Open
    L21P1-F	Ground	Continuity

    1. If the results are not as described in the table above, go to step 30.
    2. If the results are as described in the table above, continue with the next step.

15. Disconnect the connector A47AP1 from FMQGC. Check if there is an open and a short-circuit to ground as follows:

    From	To	Expected Result	Result
    A47AP1-J13	Ground	Open
    A47AP1-K13	Ground	Continuity

    1. If the results are as described in the table above, go to step 32.
    2. If the results are not as described in the table above, repair or replace the defective wiring as required and do close out.

16. Check if the indications that follow show on the LEFT TO RIGHT WING TRANSFER page:

    Reference	Indication
    VALVE OPEN POSITION SWITCH	Open
    VALVE CLOSED POSITION SWITCH	Not Closed

    1. If the results are not as described in the table above, go to step 24.
    2. If the results are as described in the table above, continue with the next step.

17. Disconnect the connector L21P1 from the LEFT CROSSOVER SOV. Check for voltage as follows:

    LEFT CROSSOVER SOV	Expected Result	Result
    L21P1-B	28 ±2 VDC
    L21P1-D	0 VDC

    1. If the results are as described in the table above, go to step 30.
    2. If the results are not as described in the table above, continue with the next step.

18. Disconnect the connector A14P4 from SPDA 2. Check for voltage as follows:

    SPDA 2	Expected Result	Result
    A14P4-E	28 ±2 VDC
    A14P4-A	0 VDC

    1. If the results are as described in the table above, repair or replace the defective wiring as required and do close out.
    2. If the results are not as described in the table above, continue with the next step.

19. Disconnect the connectors A91P1 from EMS CDU 2 and A94P1 from EMS CDU 1. Perform a continuity check as follows:

    From	To	Result
    A91P1-43	Ground
    A94P1-43	Ground

    1. If there is continuity, perform a troubleshooting for the EMS CDUs or the SPDA 2 and do close out.
    2. If there is no continuity, continue with the next step.

20. Disconnect the connector A47AP1 from FMQGC. Perform a continuity check as follows:

    From	To	Result
    A47AP1-J12	Ground

    1. If there is no continuity, go to step 32.
    2. If there is continuity, continue with the next step.

21. Disconnect the connector AP5P1 from FUEL PANEL. Perform a continuity check as follows:

    From	To	Result
    AP5P1-35	Ground

    1. If there is no continuity, repair or replace the defective wiring as required and do close out.
    2. If there is continuity, continue with the next step.

22. Disconnect the connectors AP5P1 and AP5P2 from the FUEL PANEL, A91P1 from the EMS CDU 2 and A94P1 from the EMS CDU 1. Perform a continuity check as follows:

    From	To	Result
    AP5P1-28	A94P1-43
    AP5P2-28	A91P1-43

    1. If there is no continuity, repair or replace the defective wiring as required and do close out.
    2. If there is continuity, continue with the next step.

23. Perform a continuity check as follows:

    From	To	Result
    AP5P1-28	Ground
    AP5P2-28	Ground

    1. If there is no continuity, go to step 31.
    2. If there is continuity, repair or replace the defective wiring as required and do close out.

24. Set the WING XFER switch to left to right, on the FUEL control panel. Check if the indications that follow show on the LEFT TO RIGHT WING TRANSFER page:

    Reference	Indication
    VALVE OPEN POSITION SWITCH	Open
    VALVE CLOSED POSITION SWITCH	Not Closed

    1. If the results are not as described in the table above, go to step 26.
    2. If the results are as described in the table above, continue with the next step.

25. On the CAIMS PMAT, get access to active faults. Check if the L WING XFR VALVE/WRG FAULT show on the CAIMS PMAT.

    1. If YES, go to step 32.
    2. If NO, do close out.

26. Disconnect the connectors AP5P1 and AP5P2 from the FUEL PANEL. Perform a continuity check as follows:

    From	To	Result
    AP5P1-15	GS852
    AP5P1-33	GS852
    AP5P2-18	GS160
    AP5P2-25	GS884

    1. If there is no continuity, repair or replace the defective wiring as required and do close out.
    2. If there is continuity, continue with the next step.

27. Perform a continuity check as follows:

    From	To	Result
    AP5P1-28	AP5P1-15
    AP5P2-28	AP5P2-18
    AP5P1-34	AP5P1-15

    1. If there is no continuity, go to step 31.
    2. If there is continuity, continue with the next step.

28. Perform a continuity check as follows:

    From	To	Result
    AP5P2-52	AP5P2-18
    AP5P2-50	AP5P2-18
    AP5P2-49	AP5P2-18

    1. If there is continuity, go to step 31.
    2. If there is no continuity, continue with the next step.

29. Disconnect the connector A47AP1 from FMQGC. Check if there is an open and a short-circuit to ground as follows:

    From	To	Expected Result	Result
    A47DP1-E14	Ground	Open
    A47DP1-F14	Ground	Continuity
    A47DP1-C14	Ground	Continuity
    A47DP1-D14	Ground	Continuity

    1. If the results are not as described in the table above, repair or replace the defective wiring as required and do close out.
    2. If the results are as described in the table above, continue with next step.

30. Replace the wing-transfer shutoff-valve actuator.

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

31. Replace the FUEL control panel.

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

32. Replace the FMQGC.
33. Do close out.