Loss of the Output Bus from the DMU or FDIMU to the CFDIU

TASK 31-32-00-810-822-A
Loss of the Output Bus from the DMU or FDIMU to the CFDIU

1. Possible Causes

CFDIU [1TW]
DMU [1TV]
DMU/FDIU (FDIMU) [10TV]
wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-32-00-740-009	Read the AVIONICS STATUS on the MCDU
AMM 31-32-34-000-001	Removal of the CFDIU
AMM 31-32-34-400-001	Installation of the CFDIU
ASM 313601
AMM 31-36-34-000-001	Removal of the Data Management Unit (DMU)
AMM 31-36-34-000-002	Removal of the FDIU/DMU (FDIMU)
AMM 31-36-34-400-001	Installation of the Data Management Unit (DMU)
AMM 31-36-34-400-002	Installation of the FDIU/DMU (FDIMU)

3. Fault Confirmation
Subtask 31-32-00-740-090-A

A. Read the AVIONICS STATUS on the MCDU AMM 31-32-00-740-009.

4. Fault Isolation
Subtask 31-32-00-810-070-A

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

replace the CFDIU [1TW] AMM 31-32-34-000-001 and AMM 31-32-34-400-001.

(1) If the fault continues:

replace the DMU [1TV] (if DMU installed) AMM 31-36-34-000-001 and AMM 31-36-34-400-001.

or
replace the DMU/FDIU (FDIMU) [10TV] (if FDIMU installed) AMM 31-36-34-000-002 and AMM 31-36-34-400-002.

(a) If the fault continues:

do a check and repair the wiring ASM 313601:

1 from the CFDIU (1TW) pins AB/3F, 3G to the DMU (1TV) (if DMU installed) pins AA/11E, 11F.

or

2 from the CFDIU (1TW) pins AB/3F, 3G to the FDIMU (10TV) (if FDIMU installed) pins AA/11E, 11F.

Subtask 31-32-00-740-091-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:29:49 UTC