Loss of the Signal of the Left Green Elevator-Servocontrol Solenoid Valve by the ELAC 1

TASK 27-93-00-810-870-A
Loss of the Signal of the Left Green Elevator-Servocontrol Solenoid Valve by the ELAC 1

CAUTION: DO NOT SWAP FLIGHT CONTROL COMPUTERS. IF THERE IS A SHORT CIRCUIT, YOU WILL CAUSE DAMAGE TO A SERVICEABLE COMPUTER WHEN YOU SWAP THEM.

1. Possible Causes

solenoid valve of the servocontrol 34CE1
SERVO CTL-L ELEVATOR, INBD G [34CE1]
ELAC-1 [2CE1]
wiring of the SOL VLV1 signal from the servocontrol (34CE1) to the ELAC1 (2CE1)
ELAC-2 [2CE2]
wiring from the ELAC1 (2CE1) COM part to the ELAC1 COM part
wiring from the ELAC1 (2CE1) COM part to the ELAC1 MON part
wiring from the ELAC1 (2CE1) MON part pins AE/13A and AE/10C to the first terminal block

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 27-34-51-000-001	Removal of the Elevator Servo Control
AMM 27-34-51-000-005	Removal of the Solenoid Valve of the Elevator Servo-Control Actuator
AMM 27-34-51-400-001	Installation of the Elevator Servo Control
AMM 27-34-51-400-004	Installation of the Solenoid Valve of the Elevator Servo-Control Actuator
ASM 279307
ASM 279308
AMM 27-93-34-000-001	Removal of the ELAC
AMM 27-93-34-400-001	Installation of the ELAC
AMM 27-96-00-710-020	Operational Test of the Side Stick Assembly (Activation for the BITE Test)
AMM 27-96-00-740-001	BITE Test of the EFCS (Ground Scanning)

3. Fault Confirmation
Subtask 27-93-00-700-124-A

A. Test
(1) Do the operational test of the side stick assembly (activation for the BITE test) AMM 27-96-00-710-020.

NOTE: Before you start the operational test procedure, release the FLT CTL/ELAC 2 pushbutton switch (on this pushbutton switch the OFF legend comes on).

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

4. Fault Isolation
Subtask 27-93-00-810-117-A

A. If the tests give the maintenance message ELAC1 OR WIRING TO L G ELEV SOL VLV 34CE1:
(1) Remove the ELAC1 AMM 27-93-34-000-001.
(2) At the ELAC1 receptacle, do a check of the resistance between the pin AB/14J and the pin AE/14A ASM 279307.

NOTE: The resistance must be between 40 and 100 Ohms.

(a) If the resistance is less than 40 Ohms:

at the inboard elevator servocontrol (34CE1), do a check of the resistance of the solenoid valve between the pin C/K and the pin C/L ASM 279307.

NOTE: The resistance must be between 40 and 100 Ohms.

1 If the resistance values are out of the specified limits:
a Replace the solenoid valve of the servocontrol 34CE1 AMM 27-34-51-000-005 and AMM 27-34-51-400-004.
b Do again a check of the resistance of the solenoid valve between the pin C/K and the pin C/L of the inboard elevator servocontrol (34CE1) (40 to 100 Ohms).

If the resistance values are out of the specified limits:
. Replace the SERVO CTL-L ELEVATOR, INBD G [34CE1] AMM 27-34-51-000-001 and AMM 27-34-51-400-001.
. Replace the ELAC-1 [2CE1] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.
If the resistance values are in the specified limits:
Replace the ELAC-1 [2CE1] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.

2 If the resistance values are in the specified limits:
a Repair the wiring of the SOL VLV1 signal from the servocontrol (34CE1) to the ELAC1 (2CE1), from the pin C/K to the pin AB/14J and from the pin C/L to the pin AE/14A ASM 279307:
b Replace the ELAC-1 [2CE1] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.
(b) If the resistance is more than 100 Ohms:

at the inboard elevator servocontrol (34CE1), do a check of the resistance of the solenoid valve between the pin C/K and the pin C/L ASM 279307.

NOTE: The resistance must be between 40 and 100 Ohms.

If the resistance values are out of the specified limits:
. Replace the SERVO CTL-L ELEVATOR, INBD G [34CE1] AMM 27-34-51-000-001 and AMM 27-34-51-400-001.
. Install the ELAC1 AMM 27-93-34-400-001.
If the resistance values are in the specified limits:
Install the ELAC1 AMM 27-93-34-400-001.

2 If the resistance values are in the specified limits:
a Repair the wiring of the SOL VLV1 signal from the servocontrol (34CE1) to the ELAC1 (2CE1), from the pin C/K to the pin AB/14J and from the pin C/L to the pin AE/14A ASM 279307:
b Install the ELAC1 AMM 27-93-34-400-001.
(c) If the resistance values are in the specified limits:

See Para.(3).

(3) At the ELAC 1 receptacle, do a check of the insulation between pin AB/14J (pin AE/14A) and the ground.

NOTE: The resistance must be more than 100 Megohms.

(a) If the resistance is more than 100 Megohms:

Replace the ELAC-1 [2CE1] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.
Replace the ELAC-2 [2CE2] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.

1 If the fault continues:
Replace the solenoid valve AMM 27-34-51-000-005 and AMM 27-34-51-400-004.
2 If the fault continues:
Replace the SERVO CTL-L ELEVATOR, INBD G [34CE1] AMM 27-34-51-000-001 and AMM 27-34-51-400-001.
3 do a check of the wiring from the ELAC1 (2CE1) COM part to the ELAC1 COM part, from the pin AB/13J to the pin AB/12F ASM 279307:
a If the wiring is correct, see Para. 4_
b If the wiring is not correct:

repair it
install the ELAC1 AMM 27-93-34-400-001

4 do a check of the wiring from the ELAC1 (2CE1) COM part to the ELAC1 MON part, from the pin AB/12E to the pin AE/10D ASM 279307:
a If the wiring is correct, see Para. 5_
b If the wiring is not correct:

repair it
install the ELAC1 AMM 27-93-34-400-001

5 do a check and repair the wiring from the ELAC1 (2CE1) MON part pins AE/13A and AE/10C to the first terminal block ASM 279307:
6 Remove the ELAC-2 [2CE2] AMM 27-93-34-000-001.
7 Do a check of the wiring from the ELAC-1 [2CE1] COM part to the ELAC-2 [2CE2] MON part, from pin AB/12C to pin AE/10F ASM 279307:

if there is continuity, see Para. 8_
if there is no continuity, repair the above wiring.

8 Do a check and repair the wiring from the ELAC-2 [2CE2] MON part pin AE/10C to the first terminal block ASM 279308.
9 Install the ELAC-1 [2CE1] and the ELAC-2 [2CE2] AMM 27-93-34-400-001.
(b) If the resistance is less than 100 Megohms:

at the SERVO CTL-L ELEVATOR, INBD G [34CE1] , do a check of the insulation of the solenoid valve between pin C/K (pin C/L) and the ground.

1 If the resistance is less than 100 Megohms:
Replace the solenoid valve AMM 27-34-51-000-005 and AMM 27-34-51-400-004.
a Do again a check of the insulation of the solenoid valve between pin C/K (pin C/L) and the ground.
If the resistance is less than 100 Megohms:
. Replace the SERVO CTL-L ELEVATOR, INBD G [34CE1] AMM 27-34-51-000-001 and AMM 27-34-51-400-001.
. Replace the ELAC-1 [2CE1] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.
2 If the resistance is more than 100 Megohms:
a Repair the wiring of the solenoid valve signal from the SERVO CTL-L ELEVATOR, INBD G [34CE1] to the ELAC-1 [2CE1] .
b Replace the ELAC-1 [2CE1] AMM 27-93-34-000-001 and AMM 27-93-34-400-001.

Subtask 27-93-00-700-125-A

B. Do the tests given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:28:00 UTC