Fault Message:

LH AFT XFER SOV/WRG

Fault Code:

2844633PK

Associated CAS:

AFT XFER FAIL
(Caution)

AFT XFER FAULT
(Advisory)

Left AFT Transfer Valve is not in the position commanded and the Electrical System has not failed. The valve is commanded open and the valve is not fully open, or the valve is commanded closed and the valve is not fully closed.

• Secondary Power Distribution Assembly (SPDA) 2 (A14)
• Electrical Management System Control-and-Display Units (EMS CDU) 1 (A94)
• Electrical Management System Control-and-Display Units (EMS CDU) 2 (A91)
• Left Aft-Transfer Shut-off Valve (L36)
• AFT XFER Rotary Switch (S2)
• Fuel Management and Quantity Gauging Computer (FMQGC) (A47)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW700-45-0065 - CAIMS Nuisance Fault Messages

Forum Articles/Infoservice/Newsletter: None

1. Disconnect the left aft transfer SOV connector L36P1. Apply power to the A/C. Set the AFT XFER knob on the Fuel Control Panel to 'ON'. Perform a voltage check as follows:

   Left aft transfer SOV	Expected Result	Result
   L36P1-D	28 VDC

   1. If the results are not as described in the table above, go to step 7.
   2. If the results are as described in the table above, continue with the next step.

2. Set the AFT XFER knob on the Fuel Control Panel to 'OFF'. Perform a voltage check as follows:

   Left aft transfer SOV	Expected Result	Result
   L36P1-B	28 VDC

   1. If the results are not as described in the table above, go to step 7.
   2. If the results are as described in the table above, continue with the next step.

3. Remove power from the A/C. Remove the FMQGC and perform a continuity check as follows:

   From	To	Result
   L36P1-G	A47AP1-G14
   L36P1-F	A47AP1-H14

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

4. Perform a continuity check as follows:

   From	To	Result
   L36P1-G	Ground
   L36P1-F	Ground

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

5. Re-install the FMQGC making sure it is fully and properly inserted into the tray. Is the fault still present?

   1. If NO, do close out.
   2. If YES, continue with next step.

6. Swap the left aft transfer SOV with the right aft transfer SOV. Is the fault still present?

   1. If YES, go to step 15.
   2. If NO, replace the defective Aft Transfer SOV and do close out.

7. Remove power from the A/C. Remove the FMQGC. Remove EMS CDU 1 and EMS CDU 2. Remove the Fuel Control Panel. Perform a continuity check as follows:

   From	To	Result
   AP5P1-15	Ground
   AP5P2-18	Ground
   AP5P2-25	Ground
   AP5P2-36	A47DP1-C13
   AP5P2-39	A47DP1-D13
   AP5P2-46	A47DP1-E13
   AP5P2-44	A91P1-42
   AP5P2-54	A91P1-66
   AP5P2-53	A91P2-42
   AP5P2-55	A91P2-66
   AP5P1-44	A94P1-42
   AP5P1-54	A94P1-66
   AP5P1-53	A94P2-42
   AP5P1-55	A94P2-66

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

8. Perform a continuity check as follows:

   From	To	Result
   AP5P2-36	Ground
   AP5P2-39	Ground
   AP5P2-46	Ground
   AP5P2-44	Ground
   AP5P2-54	Ground
   AP5P2-53	Ground
   AP5P2-55	Ground
   AP5P1-44	Ground
   AP5P1-54	Ground
   AP5P1-53	Ground
   AP5P1-55	Ground

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

9. Perform a continuity check directly on the Fuel Control Panel with the AFT XFER switch in various positions as follows:

   Fuel Control Panel		Switch position
   From	To	Auto	ON	OFF
   AP5J2-36	AP5J2-25	Continuity	Open	Open
   AP5J2-39	AP5J2-25	Open	Continuity	Open
   AP5J2-46	AP5J2-25	Open	Open	Continuity
   AP5J2-44	AP5J1-15	Open	Continuity	Open
   AP5J2-54	AP5J1-15	Open	Continuity	Open
   AP5J2-53	AP5J1-15	Open	Continuity	Open
   AP5J2-55	AP5J1-15	Open	Continuity	Open
   AP5J1-44	AP5J2-18	Open	Continuity	Open
   AP5J1-54	AP5J2-18	Open	Continuity	Open
   AP5J1-53	AP5J2-18	Open	Continuity	Open
   AP5J1-55	AP5J2-18	Open	Continuity	Open

   1. If the continuity check results are not as per the table above, replace the AFT XFER switch or the Fuel Control Panel as required and do close out.
   2. If the continuity check results are as per the table above, continue with next step.

10. Disconnect SPDA 2 connector A14P2. Perform a continuity check as follows:

    From	To	Result
    L36P1-B	A14P2-E
    L36P1-D	A14P2-D

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

11. Perform a continuity check as follows:

    From	To	Result
    L36P1-B	Ground
    L36P1-D	Ground

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

12. Swap SPDA 2 with SPDA 3. Is the fault still present?

    1. If NO, replace SPDA 2 and do close out.
    2. If YES, continue with next step.

13. Disconnect EMS CDU 1, leaving EMS CDU 2 connected and test the system again. Is the fault still present?

    1. If NO, replace EMS CDU 1 and do close out.
    2. If YES, continue with next step.

14. Reconnect EMS CDU 1 and disconnect EMS CDU 2. Test the system again. Is the fault still present?

    1. If NO, replace EMS CDU 2 and do close out.
    2. If YES, continue with next step.

15. Replace the FMQGC.
16. Do close out.