Loss of the Bus Output from the AMU to the CFDIU

TASK 31-32-00-810-910-A
Loss of the Bus Output from the AMU to the CFDIU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-51-34-000-001	Removal of the Audio Management Unit (AMU) (1RN)
AMM 23-51-34-400-001	Installation of the Audio Management Unit (AMU) (1RN)
AMM 31-32-00-740-003	Ground Scanning of the CFDIU
ASM 313205
AMM 31-32-34-000-001	Removal of the CFDIU
AMM 31-32-34-400-001	Installation of the CFDIU

3. Fault Confirmation
Subtask 31-32-00-865-152-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	COM/AUDIO/FLT/INTPH	9RN	G08
** ON A/C NOT FOR ALL
49VU	INT 1 + 2	9RN	G08
** ON A/C ALL
121VU	COM NAV/SELCAL	8RN	M04

Subtask 31-32-00-740-266-A

B. Test
(1) Do the ground scanning of the CFDIU AMM 31-32-00-740-003.

4. Fault Isolation
Subtask 31-32-00-810-160-A

A. If the test gives the maintenance message NO AMU DATA:

(1) If the fault continues:

(2) If the fault continues:

do a check and repair the wiring from the CFDIU (1TW) to the AMU (1RN) from pins AB/10F, 10G to pins AB/15B, 15A ASM 313205.

Subtask 31-32-00-740-267-A

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

[Rev.8 from Aug 2018] 2026.04.04 04:29:57 UTC