W DOC AIRBUS | TSM A320F

Failure of the Diode Module Related to the GCU 2

TASK 24-20-00-810-960-A
Failure of the Diode Module Related to the GCU 2

1. Possible Causes
  • GCU-2 [1XU2]
  • DIODE MODULE (2422VD)
  • wiring
  • BTC-2 [11XU2]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
ASM 242203
AMM 24-22-34-000-001
Removal of the GCU-1(2)
AMM 24-22-34-400-001
Installation of the GCU-1(2)
AMM 24-22-55-000-001
Removal of the Contactors
AMM 24-22-55-400-002
Installation of the Contactors
AMM 24-41-00-740-002
Operational Check of the GAPCU via the CFDS
3. Fault Confirmation
Subtask 24-20-00-740-114-A ** ON A/C NOT FOR ALL
A. Test
   (1) 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.A.
     (b) If the BITE test gives the message TEST PASSED:
  • stop the trouble shooting.
4. Fault Isolation
Subtask 24-20-00-810-234-A ** ON A/C NOT FOR ALL
A. If the BITE test gives the message TEST FAILED:
  • Push the line key adjacent to the TEST FAILED message.
   (1) If the maintenance message GCU2 (1XU2)/DIODE MODULE (2422VD) comes into view associated with the fault code 159 (PRR SSR/DIODE keyword):
     (a) If the fault continues:
  • Replace the DIODE MODULE (2422VD)
   (2) If the maintenance message GCU2 (1XU2)/DIODE MODULE (2422VD) comes into view associated with the fault code 274 (PRR SSR/DIODE keyword):
     (a) If the fault continues:
  • Do a check and repair the wiring between the GCU 2 and the GLC 2 auxiliary control relay (4XU2) ASM 242203 for a short to 28VDC between:
    . Pin AB/10J of the GCU 2 and pin A/C3 of the ELEC/GEN 2 pushbutton switch (3XU2)
    . Pin A/C1 of the ELEC/GEN 2 pushbutton switch and pin A/X1 of the GLC 2 auxiliary control relay.
     (b) If the fault continues:
  • Do the "BTC LOCKOUT FAILURE" trouble shooting procedure given in paragraph 4.B.
     (c) If the fault continues:
  • Replace the DIODE MODULE (2422VD)
Subtask 24-20-00-810-235-A ** ON A/C NOT FOR ALL
B. Do the BITE test of the GAPCU AMM 24-41-00-740-002:
   (1) If the BITE test gives the message GCU 2 (1XU2):
   (2) If the BITE test gives the message TEST PASSED:
  • Do a check of the wiring for a short to ground between pin B/29 of the BTC 2 and pin AA/4C of the GCU 2 ASM 242203.
     (a) If there is a short to ground:
  • Repair or replace as necessary.
     (b) If there is no short to ground:
  • Do a check of the coil return wiring for a short to ground between pin B/5 of the BTC 2 and pin AA/9A of the GCU 2 ASM 242203.
       1 If there is a short to ground:
  • Repair or replace as necessary.
       2 If there is no short to ground:
  • Do a check of the BTC 2 auxiliary status-contact between pin B/29 and pin B/27 (normally open) ASM 242203.
         a If there is continuity:
         b If there is no continuity:
Subtask 24-20-00-740-115-A ** ON A/C NOT FOR ALL
C. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:26:28 UTC
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