Skin Air Outlet-Valve or Skin Air Inlet-Valve Inoperative due to a Failure of the AEVC

TASK 21-26-00-810-842-A
Skin Air Outlet-Valve or Skin Air Inlet-Valve Inoperative due to a Failure of the AEVC

1. Possible Causes

AEVC [10HQ]
wiring
VALVE-SKIN AIR OUTLET, AVNCS VENT [22HQ]
VALVE-SKIN AIR INLET, AVNCS VENT [15HQ]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 21-26-00-710-001	Operational Check of the Avionics Equipment Ventilation-System via MCDU
AMM 21-26-00-710-008	Operational Test to Read the CFDS for CLASS 3 Faults of the AEVC
AMM 21-26-00-710-009	Operational Test to Read the CFDS for LAST LEG REPORT of the AEVC
ASM 212602
ASM 212603
AMM 21-26-34-000-001	Removal of the Avionics Equipment Ventilation Computer (AEVC)
AMM 21-26-34-400-001	Installation of the Avionics Equipment Ventilation Computer (AEVC)
AMM 21-26-52-000-001	Removal of the Avionics-Ventilation Skin Air-Inlet-Valve
AMM 21-26-52-400-001	Installation of the Avionics-Ventilation Skin Air-Inlet-Valve
AMM 21-26-53-000-002	Removal of the Skin Air Outlet-Valve
AMM 21-26-53-400-001	Installation of the Skin Air Outlet-Valve

3. Fault Confirmation
Subtask 21-26-00-865-079-A

A. Table of the circuit breakers used in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	AIR COND/AVNCS/VENT/MONG	3HQ	Y17

Subtask 21-26-00-710-125-A

B. Test
(1) Do the reset of the AEVC (10HQ).
(a) Open the circuit breaker AIR COND/AVNCS/VENT/MONG (3HQ).
(b) Wait for five seconds.
(c) Close the circuit breaker AIR COND/AVNCS/VENT/MONG (3HQ).
(2) Do the operational test of the avionics equipment ventilation from the Multipurpose Control and Display Unit (MCDU) AMM 21-26-00-710-001.
(3) Read the LAST LEG REPORT of the AEVC AMM 21-26-00-710-009.
(4) Read the CLASS 3 faults of the AEVC AMM 21-26-00-710-008.

4. Fault Isolation
Subtask 21-26-00-810-099-A

A. If the fault symptom is identified by the ECAM warning VENT AVNCS SYS FAULT and the maintenance message AEVC:

NOTE: On ground, the ECAM warning VENT SKIN VALVE FAULT cannot come into view during maintenance operations. It is replaced by the ECAM warning VENT AVNCS SYS FAULT.

Replace the AEVC [10HQ] AMM 21-26-34-000-001 and AMM 21-26-34-400-001.

(1) If the fault continues:

Do a check of the wiring between pin 2 of the AIR COND/AVNCS/VENT/MONG circuit breaker (3HQ) and pin AA/1A of the AEVC (10HQ).

(a) If the wiring is not correct:

Repair the wiring .

(b) If the wiring is correct:

Replace the VALVE-SKIN AIR OUTLET, AVNCS VENT [22HQ] AMM 21-26-53-000-002 and AMM 21-26-53-400-001.

Replace the VALVE-SKIN AIR INLET, AVNCS VENT [15HQ] AMM 21-26-52-000-001 and AMM 21-26-52-400-001.

1 If the fault continues:

Do a check of the wiring between the AEVC (10HQ) and the skin air-inlet valve (15HQ) ASM 212603:
. pin AA/4B and pin A/C
. pin AA/4A and pin A/A
. pin AB/4B and pin A/M
. pin AB/4A and pin A/J.

a If the wiring is not correct:

Repair the wiring .

b If the wiring is correct:

Do a check and repair the wiring between the AEVC (10HQ) and the skin air-outlet valve (22HQ) ASM 212602:
. pin AA/3A and pin A/A
. pin AA/3B and pin A/C
. pin AA/3C and pin A/E
. pin AB/3A and pin A/J
. pin AB/3B and pin A/M
. pin AB/3C and pin A/R.

Subtask 21-26-00-710-126-A

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

[Rev.8 from Aug 2018] 2026.04.04 04:24:39 UTC