Loss of the ACS1 Signal of the ELAC2 MON Side

TASK 27-90-00-810-815-A
Loss of the ACS1 Signal of the ELAC2 MON Side

1. Possible Causes

ELAC-2 [2CE2]
SEC-2 [1CE2]
wiring of the ACS1 SPLY signal from the ELAC2 MON side to the COM side
wiring of the ACS1 SPLY MON signal from the ELAC2 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)
ASM 279308
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)
AMM 29-23-00-863-001	Pressurize the Green Hydraulic System from the Yellow Hydraulic System through the PTU with the Electric Pump
AMM 29-23-00-864-001	Depressurize the Green and Yellow Hydraulic Systems after Operation of the PTU
AMM 29-24-00-863-001	Pressurize the Yellow Hydraulic System with the Electric Pump
AMM 29-24-00-864-001	Depressurize the Yellow Hydraulic System

3. Fault Confirmation
Subtask 27-90-00-860-050-A

A. Aircraft Maintenance Configuration
(1) Pressurize the Green and Yellow hydraulic systems AMM 29-23-00-863-001 and AMM 29-24-00-863-001.
(2) Depressurize the Green and Yellow hydraulic systems AMM 29-23-00-864-001 and AMM 29-24-00-864-001.

Subtask 27-90-00-740-077-A

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

4. Fault Isolation
Subtask 27-90-00-810-064-A

A. If the ground scanning gives at least two maintenance messages of the list below:
ELAC2 MON OR INPUT OF THS ACTR XDCR1 9CE
ELAC2 OR WIRING FROM L ELEV POS MON XDCR
ELAC2 OR WIRING FROM R ELEV POS MON XDCR
ELAC2 OR WIRING FROM L B ELEV MODE XDCR 34CE3
ELAC2 OR WIRING FROM R Y ELEV MODE XDCR 34CE4
(1) Remove the ELAC2 AMM 27-93-34-000-001 and the SEC2 AMM 27-94-34-000-001.
(2) At the ELAC2 receptacle, do a check of the resistance between the pin AB/7K and the pin AB/8K ASM 279308:
(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-2 [2CE2] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.
3 Replace the SEC-2 [1CE2] AMM 27-94-34-000-001 and AMM 27-94-34-400-001.
(b) If the resistance value is more than 10 Ohms:

do a check of the wiring of the ACS1 SPLY signal from the ELAC2 MON side to the COM side ASM 279308:
. pins AE/1J and AE/1K to pins AE/11B and AE/10B of the ELAC2 MON side
. pins AE/10A and AE/11A of the ELAC2 MON side to pins AB/8J and AB/7J of the ELAC2 COM side.

1 If the wiring is not correct:

repair it
install the ELAC2 AMM 27-93-34-400-001 and the SEC2 AMM 27-94-34-400-001.

a If the fault continues:

replace the ELAC-2 [2CE2] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.

2 If the wiring is correct:
a Replace the ELAC-2 [2CE2] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.
b Install the SEC2 AMM 27-94-34-400-001.
c If the fault continues:

do a check and repair the wiring of the ACS1 SPLY MON signal from the ELAC2 COM side to the first terminal block , pins AB/7K and AB/8K ASM 279308.
if the wiring is correct, do the failure of an alternating current supply (ACS) procedure (Ref. TSM TASK 27-90-00-810-801).

Subtask 27-90-00-740-078-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:27:52 UTC