APU AUTO SHUTDOWN - OVERSPEED, APU Speed higher than 106 % (N)

TASK 49-00-81-810-801-A
APU AUTO SHUTDOWN - OVERSPEED, APU Speed higher than 106 % (N)

1. Possible Causes

NO LRU DETECTED
FUEL CONTROL UNIT (P19)
ELECTRONIC CONTROL BOX [59KD]
FUEL CONTROL UNIT (8022KM)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 49-00-00-860-008	APU Start by External Power
AMM 49-32-11-000-003	Removal of the Fuel Control Unit (FCU) (131-9(A))
AMM 49-32-11-400-003	Installation of the Fuel Control Unit (FCU) (131-9(A))
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))

3. Fault Confirmation
Subtask 49-00-81-710-120-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
NO LRU DETECTED

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

4. Fault Isolation
Subtask 49-00-81-810-091-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:

OVERSPEED
FUEL CONTROL UNIT P19 / ECB (59KD)

associated with the Fault Code Number (FCN) 201

replace the FUEL CONTROL UNIT (P19) AMM 49-32-11-000-003 and AMM 49-32-11-400-003.

(1) If the fault continues:

replace the ELECTRONIC CONTROL BOX [59KD] AMM 49-61-34-000-003 and AMM 49-61-34-400-003.

Subtask 49-00-81-810-091-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:

OVERSPEED
FUEL CONTROL UNIT (8022KM) / ECB (59KD)

associated with the Fault Code Number (FCN) 201

replace the FUEL CONTROL UNIT (8022KM) AMM 49-32-11-000-003 and AMM 49-32-11-400-003.

(1) If the fault continues:

replace the ELECTRONIC CONTROL BOX [59KD] AMM 49-61-34-000-003 and AMM 49-61-34-400-003.

Subtask 49-00-81-710-121-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:34:31 UTC