Incorrect Air/Ground Discrete Signal between LGCIU 2 and Weather Radar (WXR) Transceiver

TASK 34-41-00-810-856-A
Incorrect Air/Ground Discrete Signal between LGCIU 2 and Weather Radar (WXR) Transceiver

1. Possible Causes

wiring from LGCIU 2 to WXR transceiver 1
wiring from LGCIU 2 to WXR transceiver 2
LGCIU-2 [5GA2]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 32-31-71-000-001	Removal of the LGCIU
AMM 32-31-71-400-001	Installation of the LGCIU
AMM 32-69-00-860-001	Simulation of Flight (With Aircraft on Ground)
AMM 34-41-33-000-004	Removal of the Weather Radar Transceiver
AMM 34-41-33-400-003	Installation of the Weather Radar Transceiver
FOR [1SQ1] (XCVR-WEATHER RADAR, 1)
ASM 344101
FOR [1SQ2]
ASM 344101

3. Fault Confirmation
Subtask 34-41-00-700-051-B

A. Test
Not Applicable

4. Fault Isolation
Subtask 34-41-00-810-121-B

A. Do the step(s) that follow(s):
(1) Remove WXR transceiver 1 and 2 AMM 34-41-33-000-004.
(2) Remove LGCIU 2 AMM 32-31-71-000-001.
(3) Do a check and repair:
(a) FOR [1SQ1] (XCVR-WEATHER RADAR, 1)

The wiring from LGCIU 2 to WXR transceiver 1 ASM 344101: pin AB/6D and pin AB/10K.

(b) FOR [1SQ2]

The wiring from LGCIU 2 to WXR transceiver 2 ASM 344101: pin AB/8D and pin AB/10K.

(4) Install LGCIU 2 AMM 32-31-71-400-001.

Subtask 34-41-00-810-122-B

B. Do a Flight Simulation AMM 32-69-00-860-001:

Select LGCIU 2 for WXR transceiver 1 or WXR transceiver 2.
Push the line key adjacent to the LEFT HAND indication for WXR transceiver 1 or WXR transceiver 2.
Make sure that there is a ground signal at pin AB/10K of WXR transceiver 1 and WXR transceiver 2.

(1) If there is no ground signal:

Replace the LGCIU-2 [5GA2] AMM 32-31-71-000-001 and AMM 32-31-71-400-001.

(2) Install WXR transceiver 1 and 2 AMM 34-41-33-400-003.

5. Close-up
Subtask 34-41-00-860-052-B

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:33:07 UTC