Message Name:

LH CTR XFRE PUMP/PRESS SW/WRG

Message Code:

284461DPK

Associated CAS:

CTR FUEL XFER FAIL
(Caution)

CTR XFER FAULT
(Advisory)

L CNTR TRNS PMP/PRES SWITCH FAULT shows on the CAIMS PMAT when the conditions that follow occur:

• The Left Center Transfer-Pump command is on
• The Left Center Transfer-Pump Pressure-indication is low

OR

• The Left Center Transfer-Pump command is off
• The Left Center Transfer-Pump Pressure-indication is high

NOTE: If both of the CAIMS messages L CNTR TRNS PMP/PRES SWITCH FAULT and L CNTR TRNS PUMP LMS/WRG FAULT show, troubleshoot with page first.

• Left Center Transfer-Pump Pressure-Switch (S19)
• Left Center Transfer-Pump Cartridge (B32)
• Fuel Management and Quantity Gauging Computer (FMQGC) (A47)
• Left Center Transfer-Pump Canister
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

Notice To Operators (NTO): None

Flight Operation Notifications Manual (FONM): None

Other names used for LEFT CENTER TRANSFER PUMP command signals:

• LH XFER L ENG RUN
• L XFER REQUEST

Synoptic indication to be confirmed in a simulator or an aircraft.

1. Make sure Center Fuel Tank has fuel in it. Go to CENTER TRANSFER TEST page via PMAT to turn on Left Center Transfer Pump.
2. Check Pump Status/Active Faults data as table below:

   	Reference	Indication
   Pump Status	LEFT XFER PUMP PRESSURE	Not Low (Hi)
   Active Faults	L XFER PRESSURE SWITCH FAIL STATUS	Normal

   1. If the pressure is high, go to step 13.
   2. If the pressure is normal, continue with next step.

3. Does fuel quantity increase in the left wing tank?

   1. If YES (fuel is transferring), go to step 10.
   2. If NO, continue with next step.

4. Measure for 118 ±3 VAC at Left Center Transfer Pump as follows:

   Pin	Expected Result	Result
   B32P1-A	18 ±3 VAC
   B32P1-B	18 ±3 VAC
   B32P1-C	18 ±3 VAC

   1. If the power is not good, go to step 6.
   2. If the power is good, continue with next step.

5. Interchange Left Center Transfer-Pump Cartridge. Is fault still present?

   1. If NO, replace Left Center Transfer-Pump Cartridge and do close out.
   2. If YES, continue with next step.

6. Check LCTR XFER PUMP command signals from the FMQGC to EMS CDU 1 and 2 (Two signal grounds at: A94P1-67 and A91P1-67).

   1. If the ground signals exist, go to step 10.
   2. If the ground signals does not exist, continue with next step.

7. Perform a continuity check from FMQGC to Fuel Panel as follows:

   From	To	Result
   A47AP1-K15	AP5P1-2
   A47DP1-H13	AP5P1-3

   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 from Fuel Panel to EMS CDU 1 and EMS CDU 2 as follows:

   From	To	Result
   AP5P1-4	A91P1-67
   AP5P1-9	A94P1-67

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

9. Perform a continuity check inside the Fuel Panel as follows:

   From	To	Result
   AP5P1-2	AP5P1-9
   AP5P1-3	AP5P1-4

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

10. Interchange Left center pump transfer pressure switch. Is fault still present?

    1. If NO, replace left center pump transfer pressure switch and do close out.
    2. If YES, continue with next step.

11. Replace FMQGC. Is fault gone?

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

12. Replace left center pump transfer pressure canister.

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

13. Turn off Left Center Transfer Pump.
14. Check Pump Status/Active Faults data as table below:

    	Reference	Indication
    Pump Status	LEFT XFER PUMP PRESSURE	Low
    Active Faults	L XFER PRESSURE SWITCH FAIL STATUS	Normal

    1. If the pressure is low, do close out.
    2. If the pressure is normal, go to step 7.

15. Do close out.