Failure of the Generator Control Unit 2

TASK 24-20-00-810-871-A
Failure of the Generator Control Unit 2

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 242203
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 24-20-00-740-060-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the BITE test of the GAPCU AMM 24-41-00-740-002.
(a) If the BITE test gives the message TEST FAILED:

(b) If the BITE test gives the message TEST PASSED:

4. Fault Isolation
Subtask 24-20-00-810-128-A ** ON A/C NOT FOR ALL

A. If the BITE test gives the message TEST FAILED:

(1) If the maintenance message GCU2 (1XU2) comes into view:

(2) If the fault continues:

do a check and repair the wiring between the GCU 2 and the GLC 2 auxiliary control relay (4XU2) ASM 242203 for a short to 28VDC between:
. pin B/10J of the GCU 2 and pin A/C3 of the ELEC/GEN 2 pushbutton switch (3XU2)
. pin A/C1 of the ELEC/GEN 2 pushbutton switch and pin A/X1 of the GLC 2 auxiliary control relay.

Subtask 24-20-00-740-061-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:26:16 UTC