APU AUTO SHUTDOWN - SENSOR FAILURE, EGT1 Sensor Fault and ECB internal Fault (131-9(A))

TASK 49-00-81-810-814-A
APU AUTO SHUTDOWN - SENSOR FAILURE, EGT1 Sensor Fault and ECB internal Fault (131-9(A))

1. Possible Causes

EGT1 SENSOR FAILURE AND ECB INTERNAL FAILURE
EGT THERMOCOUPLE RAKE 1
ELECTRONIC CONTROL BOX [59KD]
EGT THERMOCOUPLE RAKE (8057KM1)

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 49-72-15-000-002	Removal of the Thermocouples (131-9(A))
AMM 49-72-15-400-003	Installation of the Thermocouples (131-9(A))

3. Fault Confirmation
Subtask 49-00-81-710-114-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
EGT1 SENSOR 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 49-00-81-810-088-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:

SENSOR FAIL
EGT TCPLE RAKE 1 + ECB (59KD)

associated with the Fault Code Number (FCN) 36

replace the EGT THERMOCOUPLE RAKE 1 ( AMM 49-72-15-000-002 and AMM 49-72-15-400-003) and
the ELECTRONIC CONTROL BOX [59KD] ( AMM 49-61-34-000-003 and AMM 49-61-34-400-003).

Subtask 49-00-81-810-088-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:

SENSOR FAIL
EGT TCPLE RAKE (8057KM1) AND ECB (59KD)

associated with the Fault Code Number (FCN) 36

replace the EGT THERMOCOUPLE RAKE (8057KM1) ( AMM 49-72-15-000-002 and AMM 49-72-15-400-003) and
the ELECTRONIC CONTROL BOX [59KD] ( AMM 49-61-34-000-003 and AMM 49-61-34-400-003).

Subtask 49-00-81-710-115-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:34:32 UTC