Failure of the IDG1 Clogged-Filter Switch

TASK 24-00-00-810-826-A
Failure of the IDG1 Clogged-Filter Switch

1. Possible Causes

IDG-ENG 1 [4000XU1]
wiring
GCU-1 [1XU1]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 242101
AMM 24-21-51-000-803	Removal of the Integrated Drive Generator - IDG 1(2)
AMM 24-21-51-400-803	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)
AMM 24-41-00-740-002	Operational Check of the GAPCU via the CFDS

3. Fault Confirmation
Subtask 24-00-00-740-072-A ** ON A/C NOT FOR ALL

A. Test
(1) If the CMS message IDG1 (E1-4000XU) CLOG FLTR SW/GCU1 (1XU1) comes into view with other CMS messages:
Do the trouble shooting procedure related to the other CMS messages.
(a) If there are no other CMS messages, do the BITE test of the EPGS AMM 24-41-00-740-002.

4. Fault Isolation
Subtask 24-00-00-810-101-A ** ON A/C NOT FOR ALL

A. If the BITE test of the EPGS gives the maintenance message IDG1 (E1-4000XU) CLOG FLTR SW/GCU1 (1XU1):

Do a check of the contact of the clogged filter switch on the IDG1 between pin B/5 and pin B/6 (normally open) ASM 242101.

(1) If there is continuity:

Replace IDG-ENG 1 [4000XU1] AMM 24-21-51-000-803 and AMM 24-21-51-400-803.

(2) If there is no continuity:

Do a check of the clogged-filter-switch sense wiring for a short circuit or short to ground between pin A/3A of the GCU1 and pin B/5 of the IDG1 ASM 242101.

(a) If the wiring is not correct:

Repair it.

(b) If the wiring is correct:

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

Subtask 24-00-00-710-067-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:26:09 UTC