Fault Message:

ASCA FAILED (LEVEL A)

Fault Code:

2460432DCP

Associated CAS:

ELEC SYS FAIL
(Caution)

The DC Power Center (DCPC) Primary Logic Cards (PLCs) detect a discrepancy between the Solid State Power Controller (SSPC) 5 status and its commanded state.

• Auxiliary Power Unit (APU) Starter-Contactor Assembly (ASCA) (A48)
• DC Power Center (DCPC) (A63)
• Primary Logic Card (PLC) 1
• Primary Logic Card (PLC) 2
• Primary Logic Card (PLC) 3
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

NOTE: The troubleshooting for this particular fault code should be done with only Battery Master Switch (BMS) ON. External power ON is not required.

1. Get access to the APU Battery and disconnect connector A89P2.
2. Get access to the ASCA and disconnect connector A48P2.
3. Make sure circuit breaker CB-D2 is close on CCPB.
4. Perform continuity check as follows:

   From	To	Result
   A48P2-S	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. Remove all 3 DCPC PLCs.
6. Perform continuity check as follow:

   From	To	Result
   A48P2-B	Ground
   A48P2-L	Ground

   1. If there is no continuity, go to step 10.
   2. If there is continuity, continue with next step.

7. Get access to the DCPC and disconnect connector A63P1.
8. Perform wiring checks (shorted to ground=failure) as follow:

   From	To	Result
   A48P2-	Ground
   A48P2-L	Ground

   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.

9. Replace the ASCA. Is the fault still present?

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

10. Replace DCPC.

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

11. Do close out.