Loss of the Bus of the Cabin Pressure Controller 1 by the SDAC2

TASK 31-54-00-810-933-A
Loss of the Bus of the Cabin Pressure Controller 1 by the SDAC2

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-50-00-710-001	Ground Scanning of the Central Warning System
ASM 315403
AMM 31-55-34-000-001	Removal of the SDAC
AMM 31-55-34-400-001	Installation of the SDAC

3. Fault Confirmation
Subtask 31-54-00-865-130-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AIR COND/CAB/PRESS/CTL1	1HL	D09

Subtask 31-54-00-710-299-A

B. Test
Do the ground scanning of the central warning systems AMM 31-50-00-710-001.

4. Fault Isolation
Subtask 31-54-00-810-182-B

A. If the test gives the maintenance message:
SDAC2: NO DATA FROM CPC1

(1) If the fault continues:

do a check and repair the wiring from SDAC 2 (1WV2) pins AB/13G, 13H to the first terminal block ASM 315403.

Subtask 31-54-00-710-300-A

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

[Rev.8 from Aug 2018] 2026.04.04 04:30:33 UTC