APU AUTO SHUTDOWN - LOSS OF SPEED, Speed Sensor Fault and ECB internal Fault (131-9(A))

TASK 49-00-81-810-844-A
APU AUTO SHUTDOWN - LOSS OF SPEED, Speed Sensor Fault and ECB internal Fault (131-9(A))

1. Possible Causes

SPEED SENSOR 1 FAILURE AND ECB INTERNAL FAILURE
SPEED SENSOR 2 FAILURE AND ECB INTERNAL FAILURE
SPEED SENSOR P26
ELECTRONIC CONTROL BOX [59KD]
SPEED SENSOR (8060KM)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 49-00-00-860-008	APU Start by External Power
AMM 49-61-34-000-003	Removal of the Electronic Control Box (ECB) (131-9(A))
AMM 49-61-34-400-003	Installation of the Electronic Control Box (ECB) (131-9(A))
AMM 49-71-13-000-003	Removal of the Speed Sensors (131-9(A))
AMM 49-71-13-400-003	Installation of the Speed Sensors (131-9(A))

3. Fault Confirmation
Subtask 49-00-81-710-178-A ** ON A/C NOT FOR ALL

A. Read-out of ECB Trouble-Shooting Data
(1) Put the APU MASTER SW to the ON position.
(2) Get access to the APU SHUTDOWN report.
(3) Push the '>' adjacent to LRU DATA:

the MCDU menu shows
SPEED SENSOR 1 FAILURE AND ECB INTERNAL FAILURE

SPEED SENSOR 2 FAILURE AND ECB INTERNAL FAILURE

(4) Start the APU and apply Bleed Air for 20 seconds, minimum AMM 49-00-00-860-008.

4. Fault Isolation
Subtask 49-00-81-810-125-A ** ON A/C NOT FOR ALL

A. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

LOSS OF SPEED
SPEED SENSOR P26 + ECB (59KD)

associated with the Fault Code Number (FCN) 2 or 3

replace the SPEED SENSOR P26 AMM 49-71-13-000-003 and AMM 49-71-13-400-003
and
ELECTRONIC CONTROL BOX [59KD] AMM 49-61-34-000-003 and AMM 49-61-34-400-003.

Subtask 49-00-81-810-125-B ** ON A/C NOT FOR ALL

A. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

LOSS OF SPEED
SPEED SENSOR (8060KM) AND ECB (59KD)

associated with the Fault Code Number (FCN) 2 or 3

replace the SPEED SENSOR (8060KM) AMM 49-71-13-000-003 and AMM 49-71-13-400-003
and
ELECTRONIC CONTROL BOX [59KD] AMM 49-61-34-000-003 and AMM 49-61-34-400-003.

Subtask 49-00-81-710-179-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:34:35 UTC