Loss of the IRS 3 Output Bus by the DMC 1

TASK 31-63-00-810-848-A
Loss of the IRS 3 Output Bus by the DMC 1

1. Possible Causes

DMC-1 [1WT1]
wiring

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
AMM 34-12-34-000-001	Removal of the ADIRU
AMM 34-12-34-400-001	Installation of the ADIRU

3. Fault Confirmation
Subtask 31-63-00-865-080-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	NAV PROBES/ADIRU3/PWR/SWTG	8FP	F09
** ON A/C NOT FOR ALL
49VU	NAV PROBES/ADIRU3/PWR/SWTG	8FP	F08
** ON A/C ALL
121VU	ADIRS/ADIRU/3PWR/SWTG	9FP	N09
121VU	ADIRS/ADIRU/3/26VAC AND AOA	5FP3	N07
121VU	ADIRS/ADIRU/3/115VAC	4FP3	N05
121VU	ADIRS/ADIRU/3/28VDC	6FP3	N03

Subtask 31-63-00-740-106-A ** ON A/C NOT FOR ALL

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

Subtask 31-63-00-740-106-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 31-63-00-810-096-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message DMC 1 : NO IRS 3 DATA:

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

(1) If the fault continues:

do a check and repair the wiring from the DMC 1 (1WT1) pins AA/3E, 3F to the first terminal block ASM 316201.

Subtask 31-63-00-810-096-B ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message ADIRU3(1FP3) BUS3 IR / 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:

do a check and repair the wiring from the ADIRU3(1FP3) pins AB-70C/11C to the DMC1(1WT1) pins AA/2E/2F ASM 316201.

(2) If the fault continues:

replace the ADIRU3 (1FP3) AMM 34-12-34-000-001 and AMM 34-12-34-400-001.

Subtask 31-63-00-740-107-A

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

[Rev.8 from Aug 2018] 2026.04.04 04:30:40 UTC