W DOC AIRBUS | TSM A320F

Failure of the Control Circuit of the APU GLC

TASK 24-23-00-810-818-A
Failure of the Control Circuit of the APU GLC

1. Possible Causes
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 24-22-55-000-001
Removal of the Contactors
AMM 24-22-55-400-002
Installation of the Contactors
ASM 242302
AMM 24-23-55-000-001
Removal of the APU GLC
AMM 24-23-55-400-001
Installation of the APU GLC
AMM 24-41-00-740-002
Operational Check of the GAPCU via the CFDS
AMM 24-41-00-861-002
Energize the Aircraft Electrical Circuits from the External Power
AMM 24-41-00-862-002
De-energize the Aircraft Electrical Circuits Supplied from the External Power
AMM 24-41-34-000-001
Removal of the Ground Power Control Unit (GPCU)
AMM 24-41-34-400-001
Installation of the Ground Power Control Unit (GPCU)
AMM 31-60-00-860-001
EIS Start Procedure
AMM 31-60-00-860-002
EIS Stop Procedure
AMM 71-00-00-710-003
Engine Automatic Start
AMM 71-00-00-710-028
Engine Shutdown
AMM 71-00-00-860-814
Shutdown of the Engine
AMM 71-00-00-860-823
Start the Engine (Normal Automatic Start)
3. Fault Confirmation
Subtask 24-23-00-740-056-A ** ON A/C NOT FOR ALL
A. Test
   (1) If the warning APU GEN FAULT came into view when GEN 1 became available:
  • Go to Para 3.B. and start engine 1.
   (2) If the warning APU GEN FAULT came into view when GEN 2 became available:
  • Go to Para 3.B. and start engine 2.
   (3) If the warning APU GEN FAULT came into view without engine start, do the BITE test of the GAPCU AMM 24-41-00-740-002.
     (a) If the BITE test gives the message TEST FAILED:
  • Do the trouble shooting given in Para 4.C.
     (b) If the BITE test gives the message TEST PASSED:
  • Do the trouble shooting given in Para 4.D.
Subtask 24-23-00-860-070-C ** ON A/C NOT FOR ALL
B. Job Set-up
   (1) Aircraft Maintenance Configuration
     (a) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
     (b) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
     (c) Start engine 1(2) AMM 71-00-00-860-823.
Subtask 24-23-00-860-070-G ** ON A/C NOT FOR ALL
B. Job Set-up
   (1) Aircraft Maintenance Configuration
     (a) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
     (b) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
     (c) Start engine 1(2) AMM 71-00-00-710-003.
Subtask 24-23-00-710-062-A ** ON A/C NOT FOR ALL
C. Test
   (1) On the upper ECAM DU:
  • If the warning APU GEN FAULT came into view when GEN 1 became available, go to Para 3.D. and Para 4.A.
  • If the warning APU GEN FAULT came into view when GEN 2 became available, go to Para 3.D. and Para 4.B.
Subtask 24-23-00-860-071-C ** ON A/C NOT FOR ALL
D. Put the aircraft back to its initial configuration.
   (1) Stop engine 1(2) AMM 71-00-00-860-814.
   (2) Do the EIS stop procedure
AMM 31-60-00-860-002.
   (3) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
   (4) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.
Subtask 24-23-00-860-071-G ** ON A/C NOT FOR ALL
D. Put the aircraft back to its initial configuration.
   (1) Stop engine 1(2) AMM 71-00-00-710-028.
   (2) Do the EIS stop procedure
AMM 31-60-00-860-002.
   (3) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
   (4) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.
4. Fault Isolation
Subtask 24-23-00-810-084-A ** ON A/C NOT FOR ALL
A. If the test confirms the fault:
   (1) Replace BTC-1 [11XU1] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.
Subtask 24-23-00-810-085-A ** ON A/C NOT FOR ALL
B. If the test confirms the fault:
   (1) Replace BTC-2 [11XU2] AMM 24-22-55-000-001 and AMM 24-22-55-400-002.
Subtask 24-23-00-810-074-A ** ON A/C NOT FOR ALL
C. If the BITE test gives the message TEST FAILED:
  • Push the line key adjacent to the TEST FAILED message.
   (1) If the maintenance message GAPCU (24XG) comes into view:
Subtask 24-23-00-810-063-C ** ON A/C NOT FOR ALL
D. If the BITE test gives the message TEST PASSED:
  • do a check of the coil of the APU GLC auxiliary control relay (4XS) for correct electrical continuity between pin X1 and pin X2 ASM 242302.
   (1) If there is no continuity:
  • replace the RELAY-APU GLC AUX CTL [4XS] .
   (2) If there is continuity:
  • do a check of the coil of the APU GLC (3XS) for correct electrical continuity between pin B3 and pin B5 ASM 242302.
     (a) If there is no continuity:
     (b) If there is continuity:
  • do a check of the wiring of the APU GLC control-circuit ASM 242302 for an open circuit between:
    . pin B/10J of the GAPCU and pin C/3 of the ELEC/APU GEN pushbutton switch (2XS)
    . pin C/1 of the ELEC/APU GEN pushbutton switch and pin X/1 of the APU GLC auxiliary control relay (4XS)
    . pin X/2 of the APU GLC auxiliary control relay and the ground
    . pin B/10J of the GAPCU and pin C/2 of the APU AVAIL relay (6KD)
    . pin C/1 of the APU AVAIL relay (6KD) and pin A/44 of the diode module 1164VD
    . pin A/43 of the diode module 1164VD and pin A/D3 of the EPC auxiliary control relay (5XG)
    . pin A/D2 of the EPC auxiliary control relay and pin B/10 of the GLC 1
    . pin A/D2 of the EPC auxiliary control relay and pin B/8 of the BTC 1
    . pin B/12 of the GLC 1, pin B/6 of the BTC 1, pin B/12 of the GLC 2 and pin B/18 of the BTC 2
    . pin B/10 of the GLC 2 and pin A/C2 of the EPC auxiliary control relay
    . pin B/20 of the BTC 2 and pin A/C2 of the EPC auxiliary control relay
    . pin A/C3 of the EPC auxiliary control relay and pin A/B2 of the APU GLC auxiliary control relay (4XS)
    . pin A/B1 of the APU GLC auxiliary control relay and pin B/24 of the EPC (3XG)
    . pin B/22 of the EPC and pin B/3 of the APU GLC (3XS)
    . pin B/5 of the APU GLC and ground.
  • do a check of the contacts of the contactors and relays of the APU GLC control circuit ASM 242302 for correct operation.
       1 If the wiring or the contacts do not operate correctly:
       2 If the wiring or the contacts operate correctly:
Subtask 24-23-00-810-063-D ** ON A/C NOT FOR ALL
D. If the BITE test gives the message TEST PASSED:
  • Do a check of the coil of the APU-GLC auxiliary control-relay (4XS) for correct electrical continuity between pin X1 and pin X2, ASM 242302.
   (1) If there is no continuity:
  • Replace the RELAY-APU GLC AUX CTL [4XS] .
   (2) If there is continuity:
  • Do a check of the coil of the APU GLC (3XS) for correct electrical continuity between pin B3 and pin B5, ASM 242302.
     (a) If there is no continuity:
     (b) If there is continuity:
  • Do a check of the wiring of the APU GLC control-circuit, ASM 242302, for an open circuit between:
    . Pin B/10J of the GAPCU (24XU) and pin C/3 of the ELEC/APU GEN pushbutton switch (2XS)
    . Pin C/1 of the ELEC/APU GEN pushbutton switch (2XS) and pin X/1 of the APU-GLC auxiliary control-relay (4XS)
    . Pin X/2 of the APU-GLC auxiliary-control relay (4XS) and the ground
    . Pin B/10J of the GAPCU and pin A/1 of the APU-GLC auxiliary control-relay (4XS)
    . Pin A/2 of the APU-GLC auxiliary-control relay (4XS) and pin A/D3 of the EPC auxiliary control-relay (5XG)
    . Pin A/D3 of the EPC auxiliary control-relay (5XG) and pin A2 of the APU control relay (6KD)
    . Pin A/D3 of the EPC auxiliary control-relay (5XG) and pin B/10 of GLC 1 (11XU1)
    . Pin A/D2 of the EPC auxiliary control-relay (5XG) and pin B/8 of BTC 1 (9XU1)
    . Pin B/12 of GLC 1 (9XU1), pin B/6 of BTC 1 (11XU1), pin B/12 of GLC 2 (9XU2) and pin B/18 of BTC 2 (11XU2)
    . Pin B/10 of GLC 2 (9XU2) and pin A/C2 of the EPC auxiliary control-relay (5XG)
    . Pin B/20 of BTC 2 (11XU2) and pin A/C2 of the EPC auxiliary control-relay (5XG)
    . Pin A/C3 of the EPC auxiliary control-relay (5XG) and pin A/B2 of the APU-GLC auxiliary control-relay (4XS)
    . Pin A/B1 of the APU GLC auxiliary control-relay and pin B/24 of EPC (3XG)
    . Pin B/22 of EPC (5XG) and pin B/3 of APU GLC (3XS)
    . Pin B/5 of the APU GLC (3XS) and ground.
       1 If the wiring is not correct:
  • Repair it.
       2 If the wiring is correct:
  • Do a check of the contacts of the contactors and relays of the APU GLC control-circuit, ASM 242302, for correct operation.
         a If the contacts of the contactors are not correct, replace the related contactor:
         b If the contacts of the contactors are correct:
Subtask 24-23-00-740-057-A ** ON A/C NOT FOR ALL
E. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:26:41 UTC
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