APU AUTO SHUT DOWN - NO ACCELERATION (Low Acceleration) (APS 3200)

TASK 49-00-00-810-900-A
APU AUTO SHUT DOWN - NO ACCELERATION (Low Acceleration) (APS 3200)

1. Possible Causes

wiring
FUEL CONTROL UNIT (8022KM)
APU [4005KM]
FUEL FLOW DIVIDER (8024KM)
ELECTRONIC CONTROL BOX [59KD]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 49-00-81-810-900-A	APU SLOW START, Start System (APS 3200)
ESPM 2052210
ESPM 2053210
ESPM 205321A
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 49-31-41-000-002	Removal of the Pilot Fuel Nozzles and Manifold (APS 3200)
AMM 49-31-41-400-002	Installation of the Pilot Fuel Nozzles and Manifold (APS 3200)
AMM 49-32-11-000-002	Removal of the Fuel Control Unit (APS 3200)
AMM 49-32-11-400-002	Installation of the Fuel Control Unit (APS 3200)
AMM 49-32-12-000-002	Removal of the Flow Divider (APS 3200)
AMM 49-32-12-400-002	Installation of the Flow Divider (APS 3200)
ASM 496102
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 49-73-00-00-

3. Fault Confirmation
Subtask 49-00-00-710-248-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 49-00-00-810-151-C ** ON A/C NOT FOR ALL

A. Maintenance Action
(1) If the APU Last Leg Report gives the maintenance message:

FUEL CTL UNIT (8022KM):
Fault Code Number: 053
Additionally:
Fault Code Number(s): 21 or 89 or 59 or 60

NOTE: The APU SHUTDOWNS report gives the maintenance message:
NO ACCELERATION - FUEL CTL UNIT (8022KM)
APU Auto Shut Down Fault Code Number: 053

do a check and repair the wiring from the ECB (59KD) AB/F11,H10,H11,J3 to the FUEL CONTROL UNIT (8022KM) P19/1,3,4,2 ASM 496102 ESPM 2052210 ESPM 2053210 ESPM 205321A.

(a) If the fault continues:

replace the FUEL CONTROL UNIT (8022KM) AMM 49-32-11-000-002 and AMM 49-32-11-400-002.

1 If the fault continues:

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

(2) If the APU Last Leg Report gives the maintenance message:

FUEL CTL UNIT (8022KM):
Fault Code Number: 053

NOTE: The APU SHUTDOWNS report gives the maintenance message:
NO ACCELERATION - FUEL CTL UNIT (8022KM)
APU Auto Shut Down Fault Code Number: 053

replace the FUEL CONTROL UNIT (8022KM) AMM 49-32-11-000-002 and AMM 49-32-11-400-002.

(a) If the fault continues:

replace the FUEL FLOW DIVIDER (8024KM) AMM 49-32-12-000-002 and AMM 49-32-12-400-002.

1 If the fault continues:

do a check if the pilot (primary) fuel nozzles are correctly attached AMM 49-31-41-000-002 and AMM 49-31-41-400-002.
Attach as necessary.

(b) If the fault continues:
Interrogate CFDS for APU fault message. Use prompts (>) to go to the fault conditions screen AMM 49-73-00-00-.

Print Fault Condition Screen and review APU speed (NA).
1 If speed (NA) is less than 30%:

Do the TSM procedure (Ref. TSM TASK 49-00-81-810-900).

2 If speed (NA) is more than or equal to 30%:

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 49-00-00-710-249-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:34:24 UTC