W DOC AIRBUS | TSM A320F

APU Leak Detection

TASK 36-22-00-810-879-A
APU Leak Detection

1. Possible Causes
  • BMC-1 [1HA1]
  • SENSING ELEMENT-OVERHEAT,WING [11HF]
  • wiring
  • OVHT SENS ELEMENT [12HF]
  • OVHT SENS ELEMENT [13HF]
  • OVHT SENS ELEMENT [14HF]
  • OVHT SENS ELEMENT [15HF]
  • OVHT SENS ELEMENT [16HF]
  • OVHT SENS ELEMENT [17HF]
  • OVHT SENS ELEMENT [18HF]
  • OVHT SENS ELEMENT [19HF]
  • CABLE ASSY [20HF]
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
9240SI
1
CONTROLLER-LOOP
 B. Referenced Information
REFERENCE
DESIGNATION
AMM 36-11-00-740-802
BITE Test of the Engine Bleed Air System (EBAS) (System Test)
AMM 36-11-34-000-001
Removal of the BMC
AMM 36-11-34-400-001
Installation of the BMC
ASM 362201
AMM 36-22-17-000-001
Removal of the APU Overheat Sensing-Elements
AMM 36-22-17-400-001
Installation of the APU Overheat Sensing-Elements
3. Fault Confirmation
Subtask 36-22-00-710-129-A ** ON A/C NOT FOR ALL
A. Test
   (1) Do the BITE test of the EBAS AMM 36-11-00-740-802.
4. Fault Isolation
Subtask 36-22-00-810-150-A ** ON A/C NOT FOR ALL
A. If the test gives the maintenance message:
APU LOOP
  • Remove BMC1 (1HA1) AMM 36-11-34-000-001.
  • On shelf 95VU, connect the 9240SI CONTROLLER-LOOP between connector 1HA1-AA/4C and the ground ASM 362201.
  • Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
   (1) If the impedance is more than 10 kOhms:
  • Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
  • Replace BMC-1 [1HA1] which is removed AMM 36-11-34-000-001 and AMM 36-11-34-400-001.
  • Refer to Para. 4.B.
  • Do a check of the correct installation of the sensing elements along the bleed duct.
  • Do a wiring check.
   (2) If the impedance is less than 10 kOhms:
  • Do a visual inspection of the sensing elements and cables on the APU loop.
     (a) If a sensing element or cable is damaged:
     (b) If no sensing element is damaged:
  • Disconnect the connector between sensing elements 15HF and 16HF.
  • Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
NOTE: You must use a dichotomy method to find the defective sensing element:
  • Disconnect a connector in the middle of the loop.
  • Measure the resistance of one of the halves.
    If the measurement is correct, you must do a check of the other half.
    If the measurement is not correct, do the same operation in the defective half again until you find the defective sensing element.
       1 If the impedance is less than 10 kOhms:
  • Disconnect the connector between sensing elements 13HF and 14HF.
  • Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
         a If the impedance is less than 10 kOhms:
  • Disconnect the connector between cable 11HF and sensing element 12HF.
  • Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
    * If the impedance is less than 10 kOhms:
    - Replace the SENSING ELEMENT-OVERHEAT,WING [11HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    - Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
    * If the impedance is less than 10 kOhms:
    - Do a check and repair the wiring between pin AA/4C of BMC1 (1HA1) and cable 11HF ASM 362201.
    - Connect all the cables or connectors disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
    * If the impedance is more than 10 kOhms:
    - Connect all the cables or connectors disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
    * If the impedance is more than 10 kOhms:
    - Disconnect the connector between sensing elements 12HF and 13HF.
    - Connect the connector between cable 11HF and sensing element 12HF.
    - Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
    * If the impedance is less than 131 kOhms:
    - Replace the OVHT SENS ELEMENT [12HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    - Connect all the cables or connectors disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
    ** If the impedance is more than 131 kOhms:
    - Replace the OVHT SENS ELEMENT [13HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    - Connect all the cables or connectors disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
         b If the impedance is more than 10 kOhms:
  • Connect the connector between sensing elements 13HF and 14HF.
  • Disconnect the connector between sensing elements 14HF and 15HF.
  • Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
    * If the impedance is less than 10 kOhms:
    - Replace the OVHT SENS ELEMENT [14HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    - Connect all the cables or connectors disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
    * If the impedance is more than 10 kOhms:
    - Replace the OVHT SENS ELEMENT [15HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    - Connect all the cables or connectors disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
       2 If the impedance is more than 10 kOhms:
  • Connect the connector between sensing element 15HF and 16HF.
  • Disconnect the connector between sensing elements 17HF and 18HF.
  • Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
         a If the impedance is less than 10 kOhms:
  • Disconnect the connector between sensing elements 16HF and 17HF.
  • Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
    ** If the impedance is less than 10 kOhms:
    - Replace the OVHT SENS ELEMENT [16HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    - Connect all the cables or connectors disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
    ** If the impedance is more than 10 kOhms:
    - Replace the OVHT SENS ELEMENT [17HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    - Connect all the cables or connectors disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
         b If the impedance is more than 10 kOhms:
  • Connect the connector between sensing elements 17HF and 18HF.
  • Disconnect the connector between sensing element 19HF and cable 20HF.
  • Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
    * If the impedance is less than 10 kOhms:
    - Disconnect the connector between sensing elements 18HF and 19HF.
    - Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
    ** If the impedance is less than 10 kOhms:
    - Replace the OVHT SENS ELEMENT [18HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    - Connect all the cables or connectors disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
    ** If the impedance is more than 10 kOhms:
    - Replace the OVHT SENS ELEMENT [19HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    - Connect all the cables or connectors disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
    * If the impedance is more than 10 kOhms.
    - Replace the CABLE ASSY [20HF] AMM 36-22-17-000-001 and AMM 36-22-17-400-001.
    - Connect all the cables or connectors disconnected.
    - Do a check of the impedance read on the 9240SI CONTROLLER-LOOP.
    ** If the impedance is less than 10 kOhms:
    - Do a check and repair the wiring between pin AA/5C of BMC1 (1HA1) and cable 20HF ASM 362201.
    - Connect all the cables or connector disconnected.
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
    ** If the impedance is more than 10 kOhms:
    - Disconnect the 9240SI CONTROLLER-LOOP from the BMC1 connector.
    - Install BMC1 (1HA1) AMM 36-11-34-400-001.
    - Refer to Para. 4.B.
Subtask 36-22-00-710-130-A ** ON A/C NOT FOR ALL
B. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:40:28 UTC
"AVIABRAIN" 2025