No automatic display of the APU System Page at APU start

TASK 49-61-00-810-813-A
No automatic display of the APU System Page at APU start

1. Possible Causes

SDAC1
SDAC2
aircraft wiring
P/BSW-APU/MASTER SW [14KD]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-36-00-740-008	Access to the Parameter Call-Up Menus
AMM 31-55-34-000-001	Removal of the SDAC
AMM 31-55-34-400-001	Installation of the SDAC
AMM 49-00-00-860-008	APU Start by External Power
AMM 49-61-34-000-003	Removal of the Electronic Control Box (ECB) (131-9(A))
AMM 49-61-34-400-003	Installation of the Electronic Control Box (ECB) (131-9(A))

3. Fault Confirmation
Subtask 49-61-00-710-074-A ** ON A/C NOT FOR ALL

A. Test
(1) On ECAM Control Panel.

Check if one SD Page Key is come on.
If one SD Page Key comes on, push on the lighted key AMM 31-36-00-740-008.

(2) Start the APU.

If the APU SD Page is automatically show, then the aircraft is not afFected by one failure AMM 49-00-00-860-008.
If the APU SD Page is not automatically show, continue trouble-shooting.

4. Fault Isolation
Subtask 49-61-00-810-066-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message SDAC FAULT:
(1) Pull SDAC1 C/B:
(a) If APU Page is show automatically when APU Switch is ON, replace SDAC1 AMM 31-55-34-000-001 AMM 31-55-34-400-001.
(b) If APU Page is not show, push SDAC1 and continue trouble-shooting.
(2) Pull SDAC2 C/B:
(a) If APU Page is show, replace SDAC2 AMM 31-55-34-000-001 AMM 31-55-34-400-001.
(b) If APU Page is not show, replace the Electronic Control Box AMM 49-61-34-000-003 AMM 49-61-34-400-003.

Subtask 49-61-00-810-067-A ** ON A/C NOT FOR ALL

B. If the fault continues:
(1) Start the APU AMM 49-00-00-860-008.

NOTE: the check of wiring is only possible with the APU started.

(2) Do the check and repair the aircraft wiring between:
(a) On Terminal Block (1853VT) check terminal 77 pin L to P/BSW-APU/MASTER SW [14KD] pin A2.
(b) On Terminal Block (1853VT) check terminal 77 pin J to SDAC2 (1WV2) input pin J.
(c) On Terminal Block (1853VT) check terminal 77 pin K to SDAC1 (1WV1) input pin K.

NOTE: Ground signal should be found along the lines.

Subtask 49-61-00-710-075-A ** ON A/C NOT FOR ALL

C. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:34:40 UTC