Loss of the ARINC 429 Data between the FWC 1 and the DMC 1

TASK 31-53-00-810-810-A
Loss of the ARINC 429 Data between the FWC 1 and the DMC 1

1. Possible Causes

DMC-1 [1WT1]
FWC-1 [1WW1]
wiring from the DMC 1 (1WT1) to the FWC 1 (1WW1)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 315205
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)
AMM 31-60-00-740-002	Perform Electronic Instrument System (EIS) Input Test
AMM 31-60-00-740-007	GROUND SCANNING Test of the DMC
AMM 31-63-34-000-001	Removal of the DMC
AMM 31-63-34-400-001	Installation of the DMC

3. Fault Confirmation
Subtask 31-53-00-865-053-A

A. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	FWS/FWC1/SPLY	3WW	F01

Subtask 31-53-00-740-056-A ** ON A/C NOT FOR ALL

B. Test
Do the EIS input test (EIS 1) AMM 31-60-00-740-002.

Subtask 31-53-00-740-056-B ** ON A/C NOT FOR ALL

B. Test
Do the Ground Scanning Test of the DMC AMM 31-60-00-740-007.

4. Fault Isolation
Subtask 31-53-00-810-059-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message:
DMC 1 : NO FWC 1 DATA

replace the DMC-1 [1WT1] , AMM 31-63-34-000-001 and AMM 31-63-34-400-001.

(1) If the fault continues:

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

(a) If the fault continues:

do a check and repair the wiring from the DMC 1 (1WT1) to the FWC 1 (1WW1) from pins AA/10A, 10B to pins AB/12F, 12G , ASM 315205.

Subtask 31-53-00-810-059-B ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message:
FWC1(1WW1) BUSX DATA/DMC1(1WT1)

replace the DMC-1 [1WT1] , AMM 31-63-34-000-001 and AMM 31-63-34-400-001.

(1) If the fault continues:

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

(a) If the fault continues:

do a check and repair the wiring from the DMC 1 (1WT1) to the FWC 1 (1WW1) from pins AD/8G, 8H to pins AB/12F, 12G , ASM 315205.

Subtask 31-53-00-740-057-A

B. Do the test given in Para. 3.B.

[Rev.8 from Aug 2018] 2026.04.04 04:40:06 UTC