W DOC AIRBUS | TSM A320F

APU EMER SHUTDOWN - EMERGENCY, Emergency Switch active (131-9(A))

TASK 49-00-81-810-803-A
APU EMER SHUTDOWN - EMERGENCY, Emergency Switch active (131-9(A))

1. Possible Causes
  • water ingress in panel 108VU
  • ELECTRONIC CONTROL BOX [59KD]
  • FIRE EMERG-STOP RELAY (5WF)
  • CTL SW-APU SHUT OFF [1KL]
  • ENG/APU FIRE PNL [1WD]
  • wiring
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 05-23-10-200-003
GENERAL VISUAL INSPECTION OF TAIL CONE APU AND ACCESSORY COMPARTMENT (EWIS)
AMM 26-13-00-710-001
Operational Test of the APU Fire and Overheat Detection System
AMM 26-22-00-710-001
Operational Test of the APU Fire-Extinguishing Loop/Squib
AMM 49-00-00-710-009
Self-Test of the ECB
AMM 49-11-11-000-004
Removal of the Power Plant (APU) (131-9(A))
AMM 49-11-11-400-004
Installation of the Power Plant (APU) (131-9(A))
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 49-62-00-710-007
Operational Test of Emergency Shutdown System (with APU SHUT OFF Switch 1KL) (131-9(A))
AMM 49-81-41-000-003
Removal of the Exhaust Muffler (131-9(A))
AMM 49-81-41-400-003
Installation of the Exhaust Muffler (131-9(A))
3. Fault Confirmation
Subtask 49-00-81-710-094-A ** ON A/C NOT FOR ALL
A. Do the subsequent checks.
   (1) Make sure that the EMER SHUT DOWN was not caused by Maintenance Action.
   (2) Make sure the APU FIRE pushbutton switch on the APU FIRE/WARN module (1WD) was not pushed by a person accidentally.
   (3) Make sure the APU SHUT OFF (1KL) switch on the external power-control panel 108VU was not pushed by a person accidentally.
   (4) Make sure that there is no water ingress in external power-control panel 108VU.
   (5) Do the test of the APU fire detection system AMM 26-22-00-710-001.
   (6) Do the ECB BITE Test AMM 49-00-00-710-009.
4. Fault Isolation
Subtask 49-00-81-810-139-A ** ON A/C NOT FOR ALL
A. If you find signs of water ingress in panel 108VU :
  • remove the APU SHUT OFF switch (1KL).
  • do a check for moisture/corrosion on the electrical connections.
  • dry the electrical connections.
  • re-install the APU SHUT OFF switch (1KL).
Subtask 49-00-81-810-075-A ** ON A/C NOT FOR ALL
B. If the tests do not confirm the fault:
  • do an inspection of the APU and the APU compartment and make sure that you do not find the signs of a fire AMM 05-23-10-200-003,
  • do a check and make sure that the APU bleed-air duct is in the correct condition and connected correctly,
  • do a check and make sure that the APU exhaust muffler is in the correct condition and connected correctly.
   (1) If you find the signs of a fire when you do the inspection of the APU and the APU compartment:
  • do the applicable repair(s).
   (2) If the APU bleed-air duct is not in the correct condition and/or connected correctly:
   (3) If the APU exhaust muffler is not in the correct condition and/or connected correctly:
   (4) If the APU bleed-air duct and the APU exhaust muffler are in the correct condition and connected correctly:
Subtask 49-00-81-810-076-A ** ON A/C NOT FOR ALL
C. If no fault was found in APU compartment:
  • do a check and make sure that the FIRE EMERG-STOP relay (5WF) is serviceable,
  • do a check and make sure that the APU SHUT OFF pushbutton switch (1KL) is serviceable AMM 49-62-00-710-007.
  • do a check and make sure the APU FIRE/WARN module (1WD) is serviceable AMM 26-13-00-710-001.
   (1) If the FIRE EMERG STOP relay (5WF) is not serviceable:
  • replace the FIRE EMERG-STOP RELAY (5WF).
   (2) If the APU SHUT OFF pushbutton switch (1KL) is not serviceable:
  • replace the CTL SW-APU SHUT OFF [1KL] .
   (3) If the APU FIRE/WARN module (1WD) is not serviceable:
  • replace the ENG/APU FIRE PNL [1WD] .
   (4) If the FIRE EMERG STOP relay (5WF), the APU SHUT OFF pushbutton switch (1KL) and the APU FIRE/WARN module (1WD) are serviceable:
  • do a check and repair the wiring :
  • from the FIRE EMERG STOP relay (5WF) A/D1 to the ECB (59KD) AB/B4.
  • from the APU FIRE/WARN module (1WD) F/S to the ECB (59KD) AB/B4.
  • from the APU SHUT OFF pushbutton switch (1KL) 1 to the ECB (59KD) AB/B4.
     (a) If the fault continues:
Subtask 49-00-81-810-077-A ** ON A/C NOT FOR ALL
D. If the APU BITE Test gives the maintenance message:

ECB 59KD:

Subtask 49-00-81-810-078-A ** ON A/C NOT FOR ALL
E. If you do not find the signs of a fire and the tests give a different maintenance message, do the trouble shooting procedure related to the maintenance message.
Subtask 49-00-81-710-095-A ** ON A/C NOT FOR ALL
F. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:34:31 UTC
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