Loss of the ADIRU input Data through the Channel B or disagree between Aircraft and Engine sensors on Engine 1

TASK 73-20-00-810-961-A
Loss of the ADIRU input Data through the Channel B or disagree between Aircraft and Engine sensors on Engine 1

1. Possible Causes

PS12 Sensing Line
T12 temperature sensor
ADIRU-1 (1PF1)
ADIRU-2 (1PF2)
ADIRU-3 (1PF3)
pitot or static probes
ECU [4000KS]
P0 inlet port

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 72-23-00-000-040	Removal of the PS12 Line
AMM 72-23-00-280-002	Inspection/Check of the PS12 line
AMM 72-23-00-400-040	Installation of the PS12 Line
AMM 73-21-40-000-001	Removal of the T12 Temperature Sensor
AMM 73-21-40-400-001	Installation of the T12 Temperature Sensor
AMM 73-21-50-000-042	Removal of the HJ9 Harness for SAC Engines
AMM 73-21-50-000-043	Removal of the HJ10 Harness for SAC Engines
AMM 73-21-50-210-001	Visual Inspection of the Wiring Harness
AMM 73-21-50-400-042	Installation of the HJ9 Harness for SAC Engines
AMM 73-21-50-400-043	Installation of the HJ10 Harness for SAC Engines
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 73-21-60-740-007	Correct Time Limited Faults (Non Asterisked) of the Engine Scheduled Maintenance Report

3. Fault Confirmation
Subtask 73-20-00-710-288-A ** ON A/C NOT FOR ALL

A. Not applicable

4. Fault Isolation
Subtask 73-20-00-810-243-A ** ON A/C NOT FOR ALL

A. The fault is triggered by the ECU if the ADIRU inputs data to the ECU (TAT, Total Pressure and Altitude) disagree with the engine sensor inputs ( PS12 Sensing Line , T12 temperature sensor , P0).
(1) If the failure message PO/P12/T12, ADC, ECU* or PO/P12/T12, ADC, ECU is displayed and one or more failure message(s) linked to the ADIRU-1 (1PF1), ADIRU-2 (1PF2), ADIRU-3 (1PF3), pitot or static probes is (are) present:

do the trouble shooting procedures related to the ADC, pitot probes or static probes failure message.

Subtask 73-20-00-810-244-A ** ON A/C NOT FOR ALL

B. If the fault message PO/P12/T12, ADC, ECU* or PO/P12/T12, ADC, ECU is displayed and no failure message linked to the ADC, static probes or pitot probes is (are) present:

Check in the Schedule Maintenance Report (SMR) or in the Class 3 Report AMM 73-21-60-740-007 for presence of failure message(s): "ECU (P0 SENSOR)", "T12 SNSR, J9, ECU", "T12 SNSR, J10, ECU", "ECU (PS12 SENSOR)".

(1) If a fault is present:

do the trouble shooting per applicable procedure.

(2) If no fault is found:

make sure there P0 inlet port located on the Pressure plate of the ECU [4000KS] is open and free from obstruction.

(a) If damage is found:

clean the P0 inlet port ,

(b) If nothing is found:

do an inspection and check of the PS12 Sensor line AMM 72-23-00-280-002.

1 if damage is found:

replace as required AMM 72-23-00-000-040 and AMM 72-23-00-400-040.

2 if nothing is found, continues the troubleshooting as follows:
(3) disconnect the J9 and J10 harnesses from the ECU (4000KS), and visually examine the ECU receptacles and the harnesses connectors for damaged pins or contamination AMM 73-21-50-210-001:
(a) If damage is found:

clean or repair damaged parts as required.

(b) If nothing is found:

replace the T12 temperature sensor AMM 73-21-40-000-001 and AMM 73-21-40-400-001.

1 If the fault continues:

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

a If the fault continues:

replace the faulty harness: J9 harness AMM 73-21-50-000-042 and AMM 73-21-50-400-042, and J10 harness AMM 73-21-50-000-043 and AMM 73-21-50-400-043.

Subtask 73-20-00-710-289-A ** ON A/C NOT FOR ALL

C. No test is required for fault repair confirmation.

No additionnal maintenance action is required if the fault is not confirmed,
Repeat the fault isolation process if the fault continues.

[Rev.8 from Aug 2018] 2026.04.04 04:41:27 UTC