Message Name:

GEN4 [LOW OIL LEVEL]

Message Code:

2424230LPS

Associated CAS:

None

Low oil level in Variable Frequency Generator (VFG) 4 is detected by the remote oil level sensing, consequently resulting in Generator 4 tripped off-line or not come on-line.

• Variable Frequency Generator (VFG) 4 (G4)
• Generator Oil Level Sensor
• Generator Control Unit (GCU) 4 (A59)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter:

• ForumNewsletter_Volume 17_Issue 18_September_10_2020 - Variable Frequency Generator (VFG) Oil System

Notice To Operators (NTO): None

Flight Operation Notifications Manual (FONM): None

A GCU patch cable (GSE REF # 24X-24-02) can be used to interchange GCU 1, GCU 2, GCU 3, GCU 4 and the APU GCU into a different position (for troubleshooting only). You can monitor the GCU faults in the CAIMS via the fault messages page.

1. Perform a check of the oil quantity in VFG 4 and service if required as per AMM TASK 24-12-00-210-802 - Visual Check of the Variable Frequency Generator (VFG) Oil System. Is the fault still present?

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

2. Disconnect GCU 4 connector A59P2 and VFG 4 connector G4P1. Perform a continuity check as follows:

   From	To	Result
   A59P2-33	Ground
   A59P2-60	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.

3. Perform a continuity check as follows:

   From	To	Result
   A59P2-33	G4P1-K
   A59P2-60	G4P1-M

   1. If there is continuity, continue with next step.
   2. If there is no continuity, repair defective wiring as required and do close out.

4. Interchange the GCU 4 with GCU 3. Is the fault still present?

   1. If YES, continue with next step.
   2. If NO, replace GCU 4 and do close out.

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