LGCIU Signal Mismatch

TASK 21-31-00-810-817-A
LGCIU Signal Mismatch

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 213102
AMM 21-31-34-000-001	Removal of the Cabin Pressure Controller
AMM 21-31-34-400-001	Installation of the Cabin Pressure Controller
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

3. Fault Confirmation
Subtask 21-31-00-710-082-A

A. Not applicable, you cannot confirm this fault on the ground.

4. Fault Isolation
Subtask 21-31-00-810-091-B

A. If the CPC 1 (11HL) CLASS 3 FAULTS gives the maintenance messsage LGCIU SIG. REPLACED (35):

(1) If the test gives a different maintenance message refer to the Fault Symptom List.
(2) If the fault continues:

do a check and repair the wiring between:
CPC 1 (11HL) AB/1B and LGCIU 1 (5GA1) AB/C3,
CPC 1 (11HL) AB/2B and LGCIU 2 (5GA2) AB/C3 ASM 213102.

(3) If the fault continues:

Subtask 21-31-00-810-092-B

B. If the CPC 2 (12HL) CLASS 3 FAULTS gives the maintenance messsage LGCIU SIG. REPLACED (35):

(1) If the test gives a different maintenance message refer to the Fault Symptom List.
(2) If the fault continues:

do a check and repair the wiring between:
CPC 2 (12HL) AB/2B and LGCIU 2 (5GA2) AB/C3,
CPC 2 (12HL) AB/1B and LGCIU 1 (5GA1) AB/C3 ASM 213102.

(3) If the fault continues:

Subtask 21-31-00-710-083-A

C. Do the test as given in the Para. 3.A.

5. Close-up
Subtask 21-31-00-860-066-A

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:24:42 UTC