Loss of the Channel A of the FADEC on Engine 2

TASK 77-00-00-810-879-A
Loss of the Channel A of the FADEC on Engine 2

1. Possible Causes

harness J9
ECU [4000KS]
control alternator

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 71-00-00-710-006	Minimum Idle Check
AMM 73-21-30-000-002	Removal of the Control Alternator
AMM 73-21-30-400-002	Installation of the Control Alternator
AMM 73-21-50-000-008	Removal of the J9 Harness
AMM 73-21-50-400-008	Installation of the J9 Harness
AMM 73-21-60-000-001	Removal of the Electronic Control Unit (ECU)
AMM 73-21-60-400-001	Installation of the Electronic Control Unit (ECU)
ASM 732518
AMM 73-29-00-710-040	Operational Test of the FADEC on the ground (with Engine Motoring)

3. Fault Confirmation
Subtask 77-00-00-710-203-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the operational test of the FADEC 2A on the ground (with engine motoring) AMM 73-29-00-710-040.

NOTE: Ignore the ECAM warning message ENG2 FADEC B FAULT when you do the test of the FADEC 2A.

Subtask 77-00-00-710-203-B ** ON A/C NOT FOR ALL

A. Test
(1) Do the operational test of the FADEC 2A on the ground (with engine motoring) AMM 73-29-00-710-040.

4. Fault Isolation
Subtask 77-00-00-810-155-A ** ON A/C NOT FOR ALL

A. If the fault symptom is identified by:

the upper ECAM warning ENG2 FADEC A FAULT
no CFDS maintenance message after the test of the FADEC 2A
the crew observation N2 higher than 15% on ground or in flight

(1) do a check for open or short to ground of the harness J9 between the ECU (4000KS) and the control alternator pins J9/4, 5, 13, 14, 15 to pins J9/2, 3, 4, 5 ASM 732518.
(a) If the wiring is not correct:

repair the above wiring.

(b) If the wiring is correct:

disconnect the harness J9 from the ECU (4000KS) and do a check of the ECU cable resistance between:
. pins 5 and 13 (< 1 Ohm)
. pins 5 and 14 (< 1 Ohm)
. pins 5 and 15 (< 1 Ohm)
. pins 5 and 4 (> 10 Megohms)
. pin 5 and the ground (> 10 Megohms).

1 If the resistance values are in the specified limits:

replace the ECU [4000KS] AMM 73-21-60-000-001 and AMM 73-21-60-400-001.

2 If the resistance values are out of the specified limits:

disconnect the harness J9 from the control alternator and do a check of the alternator resistance between:
. pins 2 and 5 (< 1 Ohm)
. pins 3 and 5 (< 1 Ohm)
. pins 4 and 5 (< 1 Ohm)
pin 5 and the ground (> 10 Megohms).

a If the resistance values are in the specified limits:

replace the harness J9 AMM 73-21-50-000-008 and AMM 73-21-50-400-008.

b If the resistance values are out of the specified limits:

replace the control alternator AMM 73-21-30-000-002 and AMM 73-21-30-400-002.

Subtask 77-00-00-710-204-A ** ON A/C NOT FOR ALL

B. Do a minimum idle check AMM 71-00-00-710-006.

[Rev.8 from Aug 2018] 2026.04.04 04:37:34 UTC