Failure of the A629 BUS from the Upper ECAM DU to the DMC2

TASK 31-63-81-810-970-A
Failure of the A629 BUS from the Upper ECAM DU to the DMC2

1. Possible Causes

wiring
DU-ECAM, UPPER [4WT1]
DMC-2 [1WT2]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 31-63-81-810-964-A	Failure of the A629 BUS from the Upper ECAM DU to the DMC1
AMM 31-60-00-720-002	Operational Test of the DMC/DU data bus
ASM 316104
AMM 31-63-22-000-001	Removal of the Display Unit
AMM 31-63-22-400-001	Installation of the Display Unit
AMM 31-63-34-000-001	Removal of the DMC
AMM 31-63-34-400-001	Installation of the DMC

3. Fault Confirmation
Subtask 31-63-81-720-095-A ** ON A/C NOT FOR ALL

A. Test
(1) make sure that the DMC1 is correctly installed AMM 31-63-34-400-001.
(2) Do the operational test of the DMC/DU Data Bus AMM 31-60-00-720-002.

4. Fault Isolation
Subtask 31-63-81-810-255-A ** ON A/C NOT FOR ALL

A. If the test gives:
(1) The maintenance message DU EWD(4WT1)/DMC1(1WT1):

Do the relative fault isolation procedure (Ref. TSM TASK 31-63-81-810-964).

(2) The maintenance message DU EWD(4WT1)/DMC2(1WT2):

Check the wiring between the DMC1 and the DMC2 ASM 316104.

(a) If the wiring is correct:

Replace the DU-ECAM, UPPER [4WT1] AMM 31-63-22-000-001 and AMM 31-63-22-400-001.

(b) If the fault continues:

Replace the DMC-2 [1WT2] AMM 31-63-34-000-001 and AMM 31-63-34-400-001.

Subtask 31-63-81-720-096-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:31:10 UTC