Internal Failure of the ECU - NVM FAULT - Engine 1 - Channel A

TASK 73-20-81-810-861-A
Internal Failure of the ECU - NVM FAULT - Engine 1 - Channel A

1. Possible Causes

ECU [4000KS]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
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)
AMM 73-29-00-710-040	Operational Test of the FADEC on the ground (with Engine Motoring)

3. Fault Confirmation
Subtask 73-20-81-710-110-A ** ON A/C NOT FOR ALL

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

4. Fault Isolation
Subtask 73-20-81-810-110-A ** ON A/C NOT FOR ALL

A. This failure message is generated when there is an internal ECU processing fault.
(1) If the failure message ECU (NVM FAULT) is not confirmed:

no maintenance action is required.

(2) If the failure message ECU (NVM FAULT) is not confirmed, but is repetitive:

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

(3) If the failure message ECU (NVM FAULT) is confirmed:

replace the ECU (4000KS) AMM 73-21-60-000-001 and AMM 73-21-60-400-001.

Subtask 73-20-81-710-184-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.A.
(1) No additional maintenance action is required if the fault is not confirmed.
(2) Repeat the fault isolation procedure if the fault continues.

[Rev.8 from Aug 2018] 2026.04.04 04:35:39 UTC