Failure of the IDG 1 Low-Oil Pressure-Switch or its Wiring

TASK 24-21-00-810-801-A
Failure of the IDG 1 Low-Oil Pressure-Switch or its Wiring

1. Possible Causes

wiring
IDG 1 internal wiring
IDG [4000XU]
GCU-1 [1XU1]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 242101
AMM 24-21-51-000-040	Removal of the Integrated Drive Generator - IDG 1(2)
AMM 24-21-51-400-040	Installation of the Integrated Drive Generator - IDG 1(2)
AMM 24-22-34-000-001	Removal of the GCU-1(2)
AMM 24-22-34-400-001	Installation of the GCU-1(2)

3. Fault Confirmation
Subtask 24-21-00-710-050-A ** ON A/C NOT FOR ALL

A. Test
Not applicable.

4. Fault Isolation

CAUTION: BEFORE YOU START THE CHECK OF IDG WIRING THAT INCLUDES CONNECTORS, EXAMINE EACH CONNECTOR TO MAKE SURE THAT THERE IS NO CONTAMINATION IN IT. IF YOU FIND CONTAMINATION, CLEAN THE CONNECTOR AND CONNECT IT AGAIN. IF THE FAILURE CONTINUES, DO THE TROUBLE SHOOTING PROCEDURE AS GIVEN BELOW.

Subtask 24-21-00-810-050-B ** ON A/C NOT FOR ALL

A. If the check of the class 3 faults of the GPCU from the CFDS gives the maintenance message CHECK GCU1 PIN A15D IDG1 PIN CA, CB WIRING:

do a check of the wiring for open circuit:
. between the GCU 1 pin A/15D and the IDG 1 pin C/A
. then between the IDG 1 pin C/B and the ground ASM 242101.

(1) If the wiring is not correct:

repair it.

(2) If the wiring is correct:

do a check of the IDG 1 internal wiring for open circuit between the pin C/A and the pin C/B, while the engine is shut down.

(a) If there is no continuity:

replace the IDG [4000XU] AMM 24-21-51-000-040 and AMM 24-21-51-400-040.

(b) If there is continuity:

replace the GCU-1 [1XU1] AMM 24-22-34-000-001 and AMM 24-22-34-400-001.

[Rev.8 from Aug 2018] 2026.04.04 04:26:29 UTC