Fault Message:

GEN4 [LOW OIL PRESSURE FAULT]

Fault Code:

2424127LPS

Associated CAS:

GEN 4 FAIL
(Advisory)

Variable Frequency Generator (VFG) 4 has tripped off-line or will not come on-line.

• Variable Frequency Generators (VFG) 4 (G4)
• Generator Control Units (GCU) 4 (A59)
• Variable Frequency Generators (VFG) 4 Oil Pressure Switch
• 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. Check oil quantity in VFG 4. Service/refill as required.

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

2. Swap VFG 4 oil pressure switch with VFG 3 oil pressure switch.

   1. If system checks are good, replace VFG 4 oil pressure switch and do close out.
   2. If fault remains, continue with next step.

3. Swap the GCU 4 with GCU 2 (physically or using the GCU patch cable).
   NOTE: Use PMAT to monitor the fault on GCU.

   1. If system checks are good, replace GCU 4 and do close out.
   2. If fault remains, continue with next step.

4. Disconnect connector GCU 4 (A59P2) and VFG 4 (G4P2).
5. Perform wiring checks (closed circuit= failure) within VFG 4 as follow:

   From	To	Result
   G4P2-A	G4P2-B

   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.

6. Replace VFG 4.
7. Do close out.