Loss of the FCU 1 Channel B Output Bus by the DMC 1

TASK 31-63-00-810-906-A
Loss of the FCU 1 Channel B Output Bus by the DMC 1

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
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
ASM 316201
AMM 31-63-34-000-001	Removal of the DMC
AMM 31-63-34-400-001	Installation of the DMC

3. Fault Confirmation
Subtask 31-63-00-865-138-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AUTO FLT/FCU/1	9CA1	B05

Subtask 31-63-00-740-222-A ** ON A/C NOT FOR ALL

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

Subtask 31-63-00-740-222-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 31-63-00-810-154-B ** ON A/C NOT FOR ALL

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

(1) If the fault continues:

do a check and repair the wiring from the DMC 1 (1WT1) pins AA/2D, 2E to the first terminal block ASM 316201.

Subtask 31-63-00-810-154-C ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message FCU1(2CA)BUS FCU1B/DMC1(1WT1):

(1) If the fault continues:

do a check and repair the wiring from the DMC 1 (1WT1) pins AA/1C, 1D to the first terminal block ASM 316201.

Subtask 31-63-00-740-223-A

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

[Rev.8 from Aug 2018] 2026.04.04 04:40:07 UTC