PAMB Sensor Signal Failure for Engine (only on Channel A)

TASK 73-21-00-810-903-A
PAMB Sensor Signal Failure for Engine (only on Channel A)

1. Possible Causes

[4000KS]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 71-00-00-810-834-A	General Troubleshooting Guidelines for Additional Troubleshooting Information
TSM TASK 71-00-00-810-835-A	Component and Harness Intermittent Troubleshooting Procedure for Guidance Troubleshooting Intermittent Faults
AMM 73-21-00-710-806	Test No.7 - EEC Operation Test (Self Test)
AMM 73-21-01-000-801	Removal of the Electronic Engine Control (EEC)
AMM 73-21-01-400-801	Installation of the Electronic Engine Control (EEC)
AMM 78-36-00-010-802	Opening of the Thrust Reverser Cowl-Doors
AMM 78-36-00-410-802	Closing of the Thrust Reverser Cowl-Doors
Ambient Air Pressure (PAMB) Sensor

3. Fault Confirmation
Subtask 73-21-00-710-153-A ** ON A/C NOT FOR ALL

A. Do the EEC system interactive test to confirm this fault AMM 73-21-00-710-806.

NOTE: The Electronic Engine Control (EEC) channel A has detected that the Ambient Air Pressure (PAMB) sensor has failed. The PAMB sensor is internal to the EEC and senses ambient air pressure through a port in the EEC housing which is reported to channel A of the EEC. The EEC is located on the fan case at the 2 o'clock position.

Refer to the general troubleshooting guidelines for additional troubleshooting information (Ref. TSM TASK 71-00-00-810-834).
Refer to the component and harness intermittent troubleshooting procedure for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-835).

(1) If the maintenance messages related to the PAMB sensor failure on channel A come back (hard fault), go to the Para. Fault Isolation.

4. Fault Isolation

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.

WARNING: REFER TO THE MSDS FOR ALL MATERIAL USED AND THE MANUFACTURER'S SAFETY INSTRUCTIONS FOR ALL EQUIPMENT USED. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.

CAUTION: MAKE SURE YOU REMOVE ELECTRICAL POWER FROM THE EEC BEFORE YOU REMOVE THE ELECTRICAL CONNECTORS. IF YOU DO NOT OBEY THIS INSTRUCTION, DAMAGE TO THE EEC CAN OCCUR.

Subtask 73-21-00-810-172-A ** ON A/C NOT FOR ALL

A. Do the steps that follow:
(1) Open the thrust reverser cowl-doors AMM 78-36-00-010-802.
(2) Replace [4000KS] AMM 73-21-01-000-801 and AMM 73-21-01-400-801.
(a) Do the test given in Para. 3.

5. Close-up
Subtask 73-21-00-860-092-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(a) Close the thrust reverser cowl-doors AMM 78-36-00-410-802.

[Rev.8 from Aug 2018] 2026.04.04 04:36:42 UTC