AP Disconnection Warning without Physical AP Disconnection

TASK 31-53-00-810-974-A
AP Disconnection Warning without Physical AP Disconnection

1. Possible Causes

FWC-1 [1WW1]
FWC-2 [1WW2]
wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 29-10-00-863-003	Pressurize the Blue Hydraulic System with a Hydraulic Ground Power-Cart
AMM 29-23-00-863-001	Pressurize the Green Hydraulic System from the Yellow Hydraulic System through the PTU with the Electric Pump
AMM 29-24-00-864-001	Depressurize the Yellow Hydraulic System
AWM 315224
AMM 31-53-34-000-001	Removal of the Flight Warning Computer (FWC)
AMM 31-53-34-400-001	Installation of the Flight Warning Computer (FWC)

3. Fault Confirmation
Subtask 31-53-00-700-058-A

A. Test
(1) Pressurize the aircraft hydraulic systems AMM 29-23-00-863-001 AMM 29-10-00-863-003.
(2) On the FCU, push the AP1(2) pushbutton switch to engage AP1(2).
(a) Make sure that the 'AUTO FLT AP OFF' warning message comes into view on the upper ECAM DU and that the AP1(2) pushbutton switch stays on (AP1(2) engaged).

4. Fault Isolation
Subtask 31-53-00-810-228-A

A. If the test confirms the fault:
(1) On the FCU, push the AP2 pushbutton switch to engage AP2.
(2) Make sure that the 'AUTO FLT AP OFF' warning message comes into view on the upper ECAM DU.
(3) Make sure that the AP2 pushbutton switch stays on (AP2 engaged) and:
(a) If the MASTER legend of the CAPT MASTER WARN light and the WARN legend of the F/O MASTER WARN light come on:

Replace FWC-1 [1WW1] AMM 31-53-34-000-001 and AMM 31-53-34-400-001.

(b) If the WARN legend of the CAPT MASTER WARN light and the MASTER legend of the F/O MASTER WARN light come on:

Replace FWC-2 [1WW2] AMM 31-53-34-000-001 and AMM 31-53-34-400-001.

Subtask 31-53-00-810-229-A

B. If the fault continues:
(1) On the FCU, push the AP1 pushbutton switch to engage AP1.
(2) Make sure that the 'AUTO FLT AP OFF' warning message comes into view on the upper ECAM DU.
(3) Make sure that the AP1 pushbutton switch stays on (AP1 engaged) and:
(a) If the MASTER legend of the CAPT MASTER WARN light and the WARN legend of the F/O MASTER WARN light come on:

Replace FWC-1 [1WW1] AMM 31-53-34-000-001 and AMM 31-53-34-400-001.

(b) If the WARN legend of the CAPT MASTER WARN light and the MASTER legend of the F/O MASTER WARN light come on:

Replace FWC-2 [1WW2] AMM 31-53-34-000-001 and AMM 31-53-34-400-001.

Subtask 31-53-00-810-227-A

C. If the fault continues:
(1) If AP2 was engaged during the test:
(a) Do a check and repair if necessary the wiring between:

FMGC-2 (1CA2) pin AB/10D to FWC-2 (1WW2) pin AD/6F,
FMGC-2 (1CA2) pin AE/12G to FWC-2 (1WW2) pin AD/8F,
FMGC-2 (1CA2) pin AA/14B to FWC-1 (1WW1) pin AD/6F,
FMGC-2 (1CA2) pin AD/14D to FWC-1 (1WW1) pin AD/8F.
AWM 315224

(2) If AP1 was engaged during the test:
(a) Do a check and repair if necessary the wiring between:

FMGC-1 (1CA1) pin AB/10D to FWC-1 (1WW1) pin AA/6D,
FMGC-1 (1CA1) pin AE/12G to FWC-1 (1WW1) pin AA/8D,
FMGC-1 (1CA1) pin AA/14B to FWC-2 (1WW2) pin AA/6D,
FMGC-1 (1CA1) pin AD/14D to FWC-2 (1WW2) pin AA/8D.
AWM 315224

5. Close-up
Subtask 31-53-00-942-051-A

A. Put the aircraft back to its initial configuration.
(1) Depressurize the Yellow hydraulic system AMM 29-24-00-864-001.

[Rev.8 from Aug 2018] 2026.04.04 04:30:22 UTC