Fault Message:

GEN1 [LOW OIL PRESSURE FAULT]

Fault Code:

2421127LPS

Associated CAS:

GEN 1 FAIL
(Advisory)

Variable Frequency Generator (VFG) 1 has tripped off-line or will not come on-line.

• Variable Frequency Generator (VFG) 1 (G1)
• Generator Control Unit (GCU) 1 (A56)
• 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 1. Service/refill as required.

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

2. Swap VFG 1 oil pressure switch with VFG 2 oil pressure switch.

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

3. Swap GCU 1 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 1 and do close out.
   2. If fault remains, continue with next step.

4. Disconnect GCU1 connector A56P2 and VFG1 connector G1P2. Perform wiring check (closed circuit = failure) on G1P2 as follows:

   From	To	Result
   G1P2-A	G1P2-B

   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.

5. Replace VFG 1.
6. Do close out.