LGCIU1/AMU Interface Fault

TASK 23-51-00-810-850-A
LGCIU1/AMU Interface Fault

1. Possible Causes

LGCIU-1 [5GA1]
AMU [1RN]
wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-51-00-740-002	BITE Test of the Audio System
ASM 235106
AMM 23-51-34-000-001	Removal of the Audio Management Unit (AMU) (1RN)
AMM 23-51-34-400-001	Installation of the Audio Management Unit (AMU) (1RN)
AMM 32-31-71-000-001	Removal of the LGCIU
AMM 32-31-71-400-001	Installation of the LGCIU
AMM 32-69-00-740-001	BITE Check of Landing-Gear Control Interface-Unit (LGCIU) With Use of MCDU to Ensure that Continuous BITE is Operative
AMM 32-69-00-860-001	Simulation of Flight (With Aircraft on Ground)

3. Fault Confirmation
Subtask 23-51-00-740-096-A

A. Test
(1) Do the BITE test of the LGCIU1 AMM 32-69-00-740-001.
(2) Make sure that all the faults are repaired, do the trouble shooting procedure related to the maintenance message.
(3) Do the BITE test of the Audio System AMM 23-51-00-740-002 with an aircraft-in-flight configuration simulated in the LGCIU1 AMM 32-69-00-860-001.

4. Fault Isolation
Subtask 23-51-00-810-099-A

A. If the test gives the maintenance message LGCIU1 (5GA1)/AMU (1RN):

Replace the LGCIU-1 [5GA1] AMM 32-31-71-000-001 and AMM 32-31-71-400-001.

(1) If the fault continues:

Replace the AMU [1RN] AMM 23-51-34-000-001 and AMM 23-51-34-400-001.

(2) If the fault continues:

Remove the LGCIU-1 [5GA1] AMM 32-31-71-000-001
Remove the AMU [1RN] AMM 23-51-34-000-001
Do a check and repair the wiring of the AIR/GROUND DISCRETE signal from the LGCIU-1 [5GA1] pin AB/12J to the AMU [1RN] pin AB/9C ASM 235106
Install the AMU [1RN] AMM 23-51-34-400-001
Install the LGCIU-1 [5GA1] AMM 32-31-71-400-001.

Subtask 23-51-00-740-097-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:25:46 UTC