Loss of the ACS1 Signal of the SEC1 COM Side

TASK 27-90-00-810-817-A
Loss of the ACS1 Signal of the SEC1 COM Side

1. Possible Causes

ELAC-1 [2CE1]
SEC-1 [1CE1]
wiring of the ACS1 SPLY XDCR signal from the SEC1 COM side to the first terminal block

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 27-90-00-810-801-A	Failure of an Alternating Current Supply (ACS)
AMM 27-93-34-000-001	Removal of the ELAC
AMM 27-93-34-400-001	Installation of the ELAC
ASM 279407
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 27-90-00-740-081-A

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

4. Fault Isolation
Subtask 27-90-00-810-066-A

A. If the ground scanning gives at least two maintenance messages of the list below:
SEC1 COM OR WIRING FROM THS ACTR XDCR2 9CE
SEC1 OR WIRING FROM L B ELEV POS XDCR 34CE3
SEC1 OR WIRING FROM R B ELEV POS XDCR 34CE4
(1) Remove the ELAC1 AMM 27-93-34-000-001 and the SEC1 AMM 27-94-34-000-001.
(2) At the SEC1 receptacle, do a check of the resistance between the pin AA/12F and the pin AA/12G ASM 279407:
(a) If the resistance is less than 10 Ohms:
1 Do this procedure (Ref. TSM TASK 27-90-00-810-801).
2 Replace the ELAC-1 [2CE1] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.
3 Replace the SEC-1 [1CE1] AMM 27-94-34-000-001 and AMM 27-94-34-400-001.
(b) If the resistance is more than 10 Ohms:
1 Replace the SEC-1 [1CE1] AMM 27-94-34-000-001 and AMM 27-94-34-400-001.
2 Install the ELAC1 AMM 27-93-34-400-001.
3 If the fault continues:

do a check and repair the wiring of the ACS1 SPLY XDCR signal from the SEC1 COM side to the first terminal block , pins AA/12F and AA/12G ASM 279407.
if the wiring is correct, do the failure of an alternating current supply (ACS) procedure (Ref. TSM TASK 27-90-00-810-801).

Subtask 27-90-00-740-082-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:27:53 UTC