Fault Message:

GCU2 [GEN CURRENT LIMIT INHIB]

Fault Code:

2422232LPS

Associated CAS:

GEN 2 FAIL
(Advisory)

The Generator Control Unit (GCU) 2 detects the current limit inhibit discrete for 5 seconds without the logic signal ±15 V Supply.

• AC Power Center (ACPC) (A54)
• Generator Control Unit (GCU) 2 (A57)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

A GCU patch cable (GSE REF # 24X-24-02) can be used to swap GCUs 1, 4 and 5 into position 2 or 3 (for troubleshooting only).

The GCU NVMs can only be downloaded at position #2 or #3.

1. Perform a continuity check within GCU 2.

   From	To	Result
   A57P2-46	Ground

   1. If there is no continuity, go to step 3.
   2. If there is continuity, continue with next step.

2. Swap the GCU 2 with GCU 3 (physically or using the GCU patch cable). Is the fault still present?

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

3. Remove all 3 PLCs inside the ACPC.
4. Perform a continuity check within ACPC.

   From	To	Result
   A54P7-n	Ground

   1. If there is continuity, go to step 6
   2. If there is no continuity, continue with next step

5. Perform a wiring check (shorted to ground = failure) between GCU 2 and ACPC.

   From	To	Result
   A54P7-n	A57P2-46

   1. If wiring checks are not good, repair wiring as required and do close out.
   2. If wiring checks are good, continue with next step.

6. Replace ACPC.
7. Do close out.