Failure of the GCU 2 Pin Programming

TASK 24-20-00-810-933-A
Failure of the GCU 2 Pin Programming

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 24-20-00-740-056-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 24-20-00-810-182-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:

Subtask 24-20-00-810-126-B ** ON A/C NOT FOR ALL

B. If the BITE test gives the message TEST PASSED:

do a check of the pin programming wiring ASM 242203 of the GCU 2:
. pin A/5A connected to ground
. pin A/3E connected to ground
. pin A/5E connected to ground
. pins A/7C, A/8A, A/2E and A/4G not connected.

NOTE: The wiring diagram of the aircraft interface with the pin programming connections is necessary to do the trouble shooting procedure.

(1) If the wiring is not correct:

(2) If the wiring is correct:

Subtask 24-20-00-740-057-A ** ON A/C NOT FOR ALL

C. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:26:25 UTC