W DOC AIRBUS | TSM A320F

APU AUTO SHUT DOWN - BACKUP OVERSPEED CIRCUIT FAILURE, Cooling Fan/PMG Assy or ECB Fault (APS 3200)

TASK 49-00-00-810-924-A
APU AUTO SHUT DOWN - BACKUP OVERSPEED CIRCUIT FAILURE, Cooling Fan/PMG Assy or ECB Fault (APS 3200)

1. Possible Causes
  • COOLING FAN/PMG ASSY (8055KM)
  • wiring
  • ELECTRONIC CONTROL BOX [59KD]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
ESPM 2052210
AMM 49-00-00-710-008
Operational Test of the APU
AMM 49-52-53-000-001
Removal of the PMG and Cooling Fan Assembly (APS 3200)
AMM 49-52-53-400-001
Installation of the PMG and Cooling Fan Assembly (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)
3. Fault Confirmation
Subtask 49-00-00-710-289-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 49-00-00-810-227-B ** ON A/C NOT FOR ALL
A. Maintenance Action
   (1) If an APU auto shutdown occurs during the operational test of the APU and the APU SHUTDOWNS report gives the maintenance message:


BACKUP OVERSPEED CIRCUIT FAILURE, ECB (59KD)
   (2) If an APU auto shutdown occurs during the operational test of the APU and the APU SHUTDOWNS report gives the maintenance message:


BACKUP OVERSPEED CIRCUIT FAILURE, ECB (59KD) or COOLING FAN/PMG ASSY
  • disconnect the connector P28 from the COOLING FAN/PMG ASSY (8055KM).
  • do a check of the wiring from the COOLING FAN/PMG ASSY (8055KM) P28/1 to the ELECTRONIC CONTROL BOX [59KD] AB/H4 ASM 496102 ESPM 2052210.
     (a) If the fault continues:
       1 If the fault continues:
Subtask 49-00-00-710-290-A ** ON A/C NOT FOR ALL
B. Do the operational test of the APU AMM 49-00-00-710-008.
[Rev.8 from Aug 2018] 2026.04.04 04:34:26 UTC
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