Loss of the Pitch Change Over Signal by the SEC1

TASK 27-93-00-810-917-A
Loss of the Pitch Change Over Signal by the SEC1

1. Possible Causes

SEC-1 [1CE1]
SEC-2 [1CE2]
wiring of the PITCH NOT AVAIL IN ELAC2 (DSI11 and DSI22) signals
wiring of the PITCH NOT AVAIL IN ELAC1 (DSI10 and DSI26) signals
wiring of the L ELEV NOT AVAIL IN SEC2 (DSI13 and DSI27) signals
wiring of the R ELEV NOT AVAIL IN SEC2 (DSI15 and DSI23) signals
wiring of the L ELEV NOT AVAIL IN SEC1 (DSI05) signal
wiring of the R ELEV NOT AVAIL IN SEC1 (DSI06) signal

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 279232
ASM 279233
ASM 279234
ASM 279235
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 27-93-00-740-180-A

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

4. Fault Isolation
Subtask 27-93-00-810-169-A

A. If the BITE test gives the maintenance message CHECK PITCH CHANGE OVER OF SEC1:

replace the SEC-1 [1CE1] AMM 27-94-34-000-001 and AMM 27-94-34-400-001.

(1) If the fault continues:

replace the SEC-2 [1CE2] AMM 27-94-34-000-001 and AMM 27-94-34-400-001.

(2) If the fault continues:
(a) Do a check of the wiring of the PITCH NOT AVAIL IN ELAC2 (DSI11 and DSI22) signals from the SEC1 (1CE1) COM part and MON part to the first terminal block ASM 279232:

if there is continuity, go to the Para. (b)
if there is no continuity, repair the above wiring.

(b) Do a check of the wiring of the PITCH NOT AVAIL IN ELAC1 (DSI10 and DSI26) signals from the SEC1 (1CE1) COM part and MON part to the first terminal block ASM 279233:

if there is continuity, go to the Para. (c)
if there is no continuity, repair the above wiring.

(c) Do a check of the wiring of the L ELEV NOT AVAIL IN SEC2 (DSI13 and DSI27) signals from the SEC1 (1CE1) COM part and MON part to the first terminal block ASM 279234:

if there is continuity, go to the Para. (d).
if there is no continuity, repair the above wiring.

(d) Do a check of the wiring of the R ELEV NOT AVAIL IN SEC2 (DSI15 and DSI23) signals from the SEC1 (1CE1) COM part and MON part to the first terminal block ASM 279234:

if there is continuity, go to the Para. (e)
if there is no continuity, repair the above wiring.

(e) Do a check of the wiring of the L ELEV NOT AVAIL IN SEC1 (DSI05) signal from the SEC1 (1CE1) COM part and MON part to the first terminal block ASM 279235:

if there is continuity, go to the Para. (f)
if there is no continuity, repair the above wiring.

(f) Do a check and repair the wiring of the R ELEV NOT AVAIL IN SEC1 (DSI06) signal from the SEC1 (1CE1) COM part and MON part to the first terminal block ASM 279235.

Subtask 27-93-00-740-181-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:28:06 UTC