Loss of the ECU 1 Bus A of the FWC 1

TASK 31-53-00-810-852-A
Loss of the ECU 1 Bus A of the FWC 1

1. Possible Causes

FWC-1 [1WW1]
wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-50-00-710-001	Ground Scanning of the Central Warning System
ASM 315203
AMM 31-53-34-000-001	Removal of the Flight Warning Computer (FWC)
AMM 31-53-34-400-001	Installation of the Flight Warning Computer (FWC)

3. Fault Confirmation
Subtask 31-53-00-710-138-A ** ON A/C NOT FOR ALL

A. Test

NOTE: This troubleshooting task is not necessary for operators who do the "one engine taxi" procedure according to FCOM, and get the maintenance message from the engine that was not in operation.

(1) Do the ground scanning of the central warning systems (FWC) AMM 31-50-00-710-001.

4. Fault Isolation
Subtask 31-53-00-810-101-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message FWC1 : NO DATA FROM ECU1-A:

replace the FWC-1 [1WW1] , AMM 31-53-34-000-001 and AMM 31-53-34-400-001.

(1) If the fault continues:

do a check and repair the wiring from FWC 1 (1WW1) pins AB/4A, 4B to the first terminal block , ASM 315203.

Subtask 31-53-00-710-139-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:30:15 UTC