APU AUTO SHUT DOWN - OVERTEMPERATURE, EGT Mismatch (APS 3200)

TASK 49-00-00-810-948-A
APU AUTO SHUT DOWN - OVERTEMPERATURE, EGT Mismatch (APS 3200)

1. Possible Causes

EGT THERMOCOUPLE 1 (8057KM1)
EGT THERMOCOUPLE 2 (8057KM2)
connetctor P30 or P31
ELECTRONIC CONTROL BOX [59KD]
APU [4005KM]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 49-70-00-810-813-A	EGT-Thermocouple 1 Defective (APS 3200)
TSM TASK 49-70-00-810-814-A	EGT-Thermocouple 2 Defective (APS 3200)
AMM 49-00-00-710-008	Operational Test of the APU
AMM 49-11-11-000-003	Removal of the Power Plant (APU) (APS 3200)
AMM 49-11-11-400-003	Installation of the Power Plant (APU) (APS 3200)
AMM 49-61-34-000-002	Removal of the Electronic Control Box (ECB) (APS 3200)
AMM 49-61-34-400-002	Installation of the Electronic Control Box (ECB) (APS 3200)
AMM 49-72-15-000-001	Removal of the Thermocouple (APS 3200)
AMM 49-72-15-400-002	Installation of the Thermocouple (APS 3200)

3. Fault Confirmation
Subtask 49-00-00-710-322-A ** ON A/C NOT FOR ALL

A. Do the operational test of the APU AMM 49-00-00-710-008.

4. Fault Isolation
Subtask 49-00-00-810-308-B ** ON A/C NOT FOR ALL

A. If the APU Last Leg Report gives the maintenance message:

EGT TC1 (8057KM1)
or
EGT TC2 (8057KM2)
Fault Code Number: 098
Additionally possible:
Fault Code Number(s):
(035 or 036) for EGT TC1 (8057KM1)
or
(037 or 038) for EGT TC2 (8057KM2)
FCN 035-038 on Class 3 Faults Page

NOTE: The APU SHUTDOWNS report gives the maintenance message:
OVERTEMPERATURE - EGT TC1 (8057KM1) or OVERTEMPERATURE - EGT TC2 (8057KM2)
APU Auto Shut Down Fault Code Number: 098

check the related EGT THERMOCOUPLE 1 (8057KM1) or EGT THERMOCOUPLE 2 (8057KM2) and its applicable connetctor P30 or P31 for good condition and replace if necessary AMM 49-72-15-000-001 and AMM 49-72-15-400-002.

(1) If the fault continues:

replace the ELECTRONIC CONTROL BOX [59KD] AMM 49-61-34-000-002 and AMM 49-61-34-400-002.

(a) If the fault continues:

replace the APU [4005KM] AMM 49-11-11-000-003 and AMM 49-11-11-400-003.

Subtask 49-00-00-710-323-A ** ON A/C NOT FOR ALL

B. Do the operational test of the APU AMM 49-00-00-710-008.

NOTE: After the subsequent flight, make sure that the fault does not continue.

(1) If the APU CLASS 3 FAULTS page gives the maintenance message EGT TC1 P30 after the subsequent flight:

do the applicable trouble shooting procedure (Ref. TSM TASK 49-70-00-810-813).

(2) If the APU CLASS 3 FAULTS page gives the maintenance message EGT TC2 P31 after the subsequent flight:

do the applicable trouble shooting procedure (Ref. TSM TASK 49-70-00-810-814).

[Rev.8 from Aug 2018] 2026.04.04 04:34:27 UTC