PARITY FAIL Message Shown on MCDU without ECAM Alerts

TASK 31-55-00-810-804-A
PARITY FAIL Message Shown on MCDU without ECAM Alerts

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 31-54-00-810-928-A	Failure of the SDAC 1 Pin Programming
TSM TASK 31-54-00-810-929-A	Failure of the SDAC 2 Pin Programming

3. Fault Confirmation
Subtask 31-55-00-710-053-A

A. Not applicable, the fault is evident.

4. Fault Isolation
Subtask 31-55-00-865-050-A

A. Table of the circuit breakers referred to in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 1WV1 (SDAC1)
49VU	SDAC/1/SPLY	3WV	F04
FOR FIN: 1WV2 (SDAC2)
121VU	EIS/SDAC/2/SPLY	2WV	Q06

Subtask 31-55-00-810-053-A

B. If the fault symptom is identified by the crew observation:
(1) Open circuit breakers 3WV and 2WV.
(2) Make sure that the FWS SDAC 1+2 FAULT message is shown on the upper ECAM display unit.
(3) Close circuit breakers 3WV and 2WV.
(a) If the FWS SDAC 1 FAULT or FWS SDAC 2 FAULT message is not shown on the upper ECAM display unit:

no other maintenance action is necessary.

(b) If the FWS SDAC 1 FAULT message is shown on the upper ECAM display unit:

do the related trouble shooting procedure (Ref. TSM TASK 31-54-00-810-928).

do the related trouble shooting procedure (Ref. TSM TASK 31-54-00-810-929).

[Rev.8 from Aug 2018] 2026.04.04 04:30:35 UTC