Fault Message:

RH DC AUX PUMP ELECT PWR/WRG

Fault Code:

2844615PK

Associated CAS:

-> FUEL XFER FAIL
(Caution)

-> FUEL XFER ON
(Caution)

R AUX FUEL PUMP
(Advisory)

Fuel Management and Quantity Gauging Computer (FMQGC) Senses that the Right wing DC Auxiliary Pump is not able to go off or on as commanded due to an Electrical Load Management System (LMS) failure.

• Load Management System (LMS)
• Right Wing DC Auxiliary Pump (B24)
• Junction Box (JB3)
• Junction Box (JB4)
• Fuel Management Quantity and Gauging Computer (FMQGC) (A47)
• Electrical Management System Control and Display Units (EMS CDU) 1 (A94)
• Electrical Management System Control and Display Units (EMS CDU) 2 (A91)
• Secondary Power Distribution Assemblies (SPDA) 3 (A15)
• Associated Wiring

1. Using CAIMS, verify if there are messages concerning the 28 VDC battery bus or SPDA 3 shown:

   1. If YES, troubleshoot them first.
   2. If NO, continue with next step.

2. Select the SPDA 3A (3B) LOAD STATUS LABEL 002 (R AUX PUMP) page, via CAIMS System Diagnostics. Set the right ENGINE RUN switch to ON, R AUX PUMPS switch/light to ON (Pushed out), and R PRIM PUMPS switch/light to OFF (Pushed in). Make sure the result that follows are met.

   Reference	Status
   LOGIC EQUATION STATE (L TRANSFER REQUEST)	ON
   VIRTUAL CIRCUIT BREAKER (SSPC CIRCUIT BREAKER)	IN
   VIRTUAL SWITCH (SSPC SW)	ON
   LOCK STATE	UNLOCKED
   VOLTAGE STATUS	PRESENT
   CURRENT STATUS	FLOWING
   TRIP STATUS (CIRCUIT BREAKER)	NOT TRIP
   FAIL STATUS (SSPC)	NOT FAILED

   1. If the above status are met, go to step 20.
   2. If one of the above status is not met, go to step 4.
   3. If more than one status is not met, continue with next step.

3. An alternative way of monitoring the result is to select SPDA 3 IN via EMS CDU 1 or CDU 2 Signboard Menu:

   	Left Column								Center Column
   Label 046	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14
   	X	X	X	X	X	X	X	X			1	1	1	1	1	1
   Reference	R AUX PUMP

   1. Bit 14: LOGIC EQUATION STATE (L TRANSFER REQUEST)
   2. Bit 15: VIRTUAL CIRCUIT BREAKER (SSPC CIRCUIT BREAKER)
   3. Bit 16: VIRTUAL SWITCH (SSPC SW)
   4. Bit 17: LOCK STATE
   5. Bit 18: VOLTAGE STATUS
   6. Bit 19: CURRENT STATUS
   7. Bit 20: TRIP STATUS (CIRCUIT BREAKER)
   8. Bit 21: FAIL STATUS (SSPC)

      1. If the above status are met, go to step 20.
      2. If one of the above status is not met, continue with next step.

4. Perform wiring check (short to ground = fail) between the SPDA 3 (A15P1) and right wing auxiliary pump (B24P1).

   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.

5. Perform a ground check at right wing auxiliary pump (B24P1).

   1. If ground is not there, go to step 7.
   2. If ground is there, continue with next step.

6. Swap the Right auxiliary pump (B24) with Left auxiliary pump (B10). Is the fault still present?

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

7. On the SPDA 3A (3B)-COMMUNICATION AND AIRCRAFT MODE page, via CAIMS System Diagnostics, monitor the ARINC communication between EMS CDU and SPDA 3.

   1. If the CDU 1 ARINC COMM OK and CDU 2 ARINC COMM OK are shown as OK, go to step 20.
   2. If the CDU 2 ARINC COMM OK is shown as invalid, go to step 12.
   3. If the CDU 1 ARINC COMM OK is shown as invalid, go to step 9.

8. An alternative way of monitoring the ARINC communication is to select SPDA 3 IN via EMS CDU 1 or CDU 2 Signboard Menu:

   	Center Column
   Label 062	21	20	19	18	17	16	15	14
   	X	X	X	X	X	1	X	1
   Reference	SPDA 3 ARINC Status

   1. Bit 14: CDU 1 ARINC COMM OK.
   2. Bit 16: CDU 2 ARINC COMM OK.

      1. If bit 14 and 16 are shown as 1, go to step 20.
      2. If bit 16 is shown as 0, go to step 12.
      3. If bit 14 is shown as 0, continue with next step.

9. Perform wiring check via TP-63 between JB3/PCB3, SPDA 3 (A15P5), and EMS CDU 1 (A94P1).

   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.

10. Perform wiring check via TP-64 between JB3/PCB3, SPDA 3 (A15P5), and EMS CDU 1 (A94P1).

    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.

11. Replace the JB3/PCB 3.

    1. If system checks are good, do close out.
    2. If fault remains, go to step 17.

12. Perform wiring check via TP-3 between JB3/PCB2, JB4/PCB2, SPDA 3 (A15P6), and EMS CDU 2 (A91P1).

    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.

13. Perform wiring check via TP-34 between JB3/PCB2, JB4/PCB2, SPDA 3 (A15P6), and EMS CDU 2 (A91P1).

    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.

14. Replace the JB3/PCB2.

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

15. Replace the JB4/PCB2.

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

16. Replace JB4.

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

17. Replace JB3.

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

18. Swap the EMS CDUs.

    1. If system checks are good, replace defected EMS CDU and do close out.
    2. If fault remains, continue with next step.

19. Swap the SPDA 3 with SPDA 2.

    1. If system checks are good, replace SPDA 3 and do close out.
    2. B.If fault remains, continue with next step.

20. Replace FMQGC.
21. Do close out.