Failure of the Override Switch 2

TASK 27-40-00-810-804-A
Failure of the Override Switch 2

1. Possible Causes

ELAC-1 [2CE1]
SEC-1 [1CE1]
wiring from the DSI-31 signal of the ELAC 1 (2CE1) to the first terminal block
wiring from the overriding signal of the THS actuator (9CE) to the first terminal block
pitch trim actuator

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 31-32-00-810-932-A	Failure of the Discrete Links
AMM 27-44-57-000-001	Removal of the Pitch Trim Actuator from the THS Actuator
AMM 27-44-57-400-001	Installation of the Pitch Trim Actuator to the THS Actuator
ASM 279312
ASM 279313
AMM 27-93-34-000-001	Removal of the ELAC
AMM 27-93-34-400-001	Installation of the ELAC
AMM 27-94-34-000-001	Removal of the SEC
AMM 27-94-34-400-001	Installation of the SEC
AMM 27-96-00-740-001	BITE Test of the EFCS (Ground Scanning)

3. Fault Confirmation
Subtask 27-40-00-700-056-A

A. Test
(1) Do the BITE test of the EFCS (ground scanning) AMM 27-96-00-740-001.

4. Fault Isolation
Subtask 27-40-00-810-053-A

A. If the BITE test gives the maintenance message:
THS ACTR OVRD SW2 9CE OF ELAC1

(1) If the fault continues:

do the trouble shooting procedure (Ref. TSM TASK 31-32-00-810-932) related to the DSI 31 discret input signal of the ELAC 1 MON, SEC 1 MON and ELAC 2 ASM 279312 and ASM 279313.

(2) If the fault continues:

(3) If the fault continues:

do a check of the wiring from the DSI-31 signal of the ELAC 1 (2CE1) to the first terminal block, COM part and MON part ASM 279312.

(a) If there is no continuity, repair the wiring.
(b) If there is continuity:

do a check of the wiring from the overriding signal of the THS actuator (9CE) to the first terminal block ASM 279312.

1 If there is no continuity, repair the wiring.
2 If there is continuity:

Subtask 27-40-00-700-057-A

B. Do the tests given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:27:35 UTC