APU AUTO SHUT DOWN - NO ACCELERATION (Deceleration), Fuel System Fault (APS 3200)

TASK 49-00-00-810-898-A
APU AUTO SHUT DOWN - NO ACCELERATION (Deceleration), Fuel System Fault (APS 3200)

1. Possible Causes

MAGNETIC DRAIN PLUG
FUEL FLOW DIVIDER (8024KM)
FUEL CONTROL UNIT (8022KM)
SECONDARY FUEL NOZZLES
wiring
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 49-31-42-000-003	Removal of the Main Fuel Nozzles and Manifold (APS 3200)
AMM 49-31-42-400-005	Installation of the Main 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-
AMM 49-91-42-200-003	Inspection of the Magnetic Drain Plug (APS 3200)

3. Fault Confirmation
Subtask 49-00-00-710-244-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 49-00-00-810-149-C ** ON A/C NOT FOR ALL

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

FUEL CTL UNIT (8022KM) / FUEL FLOW DIVIDER (8024KM):
Fault Code Number: 052

NOTE: The APU SHUTDOWNS report gives the maintenance message:
NO ACCELERATION - FUEL CTL UNIT (8022KM) / FUEL FLOW DIVIDER (8024KM)
APU Auto Shut Down Fault Code Number: 052

do a check for blockage of the air inlet.

(1) 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 EGT.

(a) If EGT is more than or equal to 650 deg.C:

do a check for contamination of the MAGNETIC DRAIN PLUG AMM 49-91-42-200-003.
if there is no contamination, do the TSM procedure (Ref. TSM TASK 49-00-81-810-900).

(b) If the EGT is less than 650 deg.C:

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

1 If the fault continues:

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

2 If the fault continues:

replace the SECONDARY FUEL NOZZLES AMM 49-31-42-000-003 and AMM 49-31-42-400-005.

3 If the fault continues:

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

4 If the fault continues:

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

Subtask 49-00-00-710-245-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