Loss of the ADIRU1 Signal to the ECU on Engine 1

TASK 71-50-00-810-828-A
Loss of the ADIRU1 Signal to the ECU on Engine 1

1. Possible Causes

harness J3
ADIRU-1 [1FP1]
ECU [4000KS]
aircraft wiring between the ADIRU1 (1FP1) and the connector 402VC1 on the pylon junction box

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 34-12-34-000-001	Removal of the ADIRU
AMM 34-12-34-400-001	Installation of the ADIRU
AWM 715104
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 732510
AWM 732525
AMM 73-29-00-710-040	Operational Test of the FADEC on the ground (with Engine Motoring)

3. Fault Confirmation
Subtask 71-50-00-710-090-A ** ON A/C NOT FOR ALL

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

4. Fault Isolation
Subtask 71-50-00-810-076-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message J3, ADC1 or J3, ADC1*:

do a check for open or short to ground of the harness J3 between the ECU (4000KS) and the connector 402VC1 on the pylon junction box, pins J3/9, 2 to pins 402VC1/28, 14 AWM 715104.

(1) If the fault continues:

(2) If the fault continues:

(3) If the fault continues:

(4) If the fault continues:

do a check and repair the aircraft wiring between the ADIRU1 (1FP1) and the connector 402VC1 on the pylon junction box, pins AA/12B, 12D to pins 402VC1/14, 28 AWM 732525 and ASM 732510.

Subtask 71-50-00-710-091-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:35:00 UTC