Excessive Cabin Altitude associated with CAB PR SYS FAULT

TASK 21-31-00-810-827-A
Excessive Cabin Altitude associated with CAB PR SYS FAULT

1. Possible Causes

PRESS CONT 1 [11HL]
PRESS CONT 2 [12HL]
OUTFLOW VALVE [10HL]
wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 21-31-00-760-001	Resistance Check of the Return Ground Connections - Cabin Pressure Controller (CPC) 1 (11HL) and 2 (12HL) and the Electronic Modules 10HL-1 and 10HL-2
CMM 213121
AMM 21-31-34-000-001	Removal of the Cabin Pressure Controller
AMM 21-31-34-400-001	Installation of the Cabin Pressure Controller
AMM 21-31-51-000-001	Removal of the Outflow Valve (From Inside)
AMM 21-31-51-000-006	Removal of the Outflow Valve (From Outside)
AMM 21-31-51-400-001	Installation of the Outflow Valve (From Inside)
AMM 21-31-51-400-006	Installation of the Outflow Valve (From Outside)

3. Fault Confirmation
Subtask 21-31-00-710-103-A

A. Do a read out of the POST FLIGHT REPORT.

4. Fault Isolation
Subtask 21-31-00-810-162-A

A. If the POST FLIGHT REPORT gives the ECAM warnings CAB PR EXCESS CAB ALT together with CAB PR SYS 1 FAULT or CAB PR SYS 2 FAULT,
(1) Make a print out of:

the POST FLIGHT REPORT,
the CPC1 and CPC2 LAST LEG REPORTS and PREVIOUS LEG REPORTS and,
if available the ECS REPORT 19.

(2) Replace the PRESS CONT 1 [11HL] and the PRESS CONT 2 [12HL]
AMM 21-31-34-000-001 and,
AMM 21-31-34-400-001.
(a) If possible do a print out of the NON-VOLATILE MEMORY read-out CMM 213121.

NOTE: It is recommended to:

advise Airbus Industrie in case excessive cabin altitude is experienced and,
provide Airbus Industrie with the information provided by the reports and read-out from work steps (1) and (2)(a).

(3) Replace the OUTFLOW VALVE [10HL]
AMM 21-31-51-000-001 and,
AMM 21-31-51-400-001 or,
AMM 21-31-51-000-006 and,
AMM 21-31-51-400-006.

NOTE: It is recommended that the removed outflow valve and controllers should be returned to the vendor for a detailed examination.

(4) Do the resistance check of the ground wiring AMM 21-31-00-760-001.

[Rev.8 from Aug 2018] 2026.04.04 04:38:51 UTC