Failure of the Override Switch 3

TASK 27-40-00-810-806-A
Failure of the Override Switch 3

1. Possible Causes

SEC-2 [1CE2]
wiring from the DSI-24 signal of the SEC 2 (1CE2) 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
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 279413
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 27-40-00-700-060-A

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

4. Fault Isolation
Subtask 27-40-00-810-055-A

A. If the BITE test gives the maintenance message:
THS ACTR OVRD SW3 9CE

(1) If the fault continues:

do a check of the wiring from the DSI-24 signal of the SEC 2 (1CE2) to the first terminal block COM part and MON part ASM 279413.

(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 279413.

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

Subtask 27-40-00-700-061-A

B. Do the tests given in Para. 3.

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