MODE SEL Pushbutton Switch FAULT Legend on

TASK 21-31-00-810-825-A
MODE SEL Pushbutton Switch FAULT Legend on

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 21-31-00-710-002	Operational Test of the Pressure Control and Monitoring
ASM 213101
AMM 21-31-34-000-001	Removal of the Cabin Pressure Controller
AMM 21-31-34-400-001	Installation of the Cabin Pressure Controller

3. Fault Confirmation
Subtask 21-31-00-710-098-A

A. Do the operational test of the pressure control and monitoring system AMM 21-31-00-710-002.

4. Fault Isolation
Subtask 21-31-00-810-138-A

A. If the FAULT legend in the pushbutton switch CABIN PRESS/MODE SEL/AUTO, which is installed on the panel 25VU, is on.

do a check of the BOARD-ANN LT TEST & INTFC [7LP] and replace it if necessary ASM 213101.

(1) If the fault continues:

do a check of the RELAY-ESS EMERGENCY (40LP) and replace it if necessary ASM 213101.

(2) If the fault continues:

replace the PRESS CONT 1 [11HL] and PRESS CONT 2 [12HL] AMM 21-31-34-000-001 and AMM 21-31-34-400-001.

(3) If the fault continues:

replace the RELAY-AUTO MODE 1 FAULT [18HL] and RELAY-AUTO MODE 2 FAULT [19HL] .
ASM 213101.

Subtask 21-31-00-710-099-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:24:43 UTC