W DOC AIRBUS | TSM A320F

The FAULT Legend of the GPWS/SYS Pushbutton Switch Does not Come on

TASK 34-48-00-810-816-A
The FAULT Legend of the GPWS/SYS Pushbutton Switch Does not Come on

1. Possible Causes
  • P/BSW-GPWS/SYS [9WZ]
  • wiring of the GPWS/SYS pushbutton switch (9WZ)
  • wiring of the annunciator light test and interface board (4LP)
  • C/B-EIS/GPWS/28VDC [2WZ]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
ESPM 2045110
AMM 34-48-00-710-001
Operational Test of GPWS Ground Self-test Function
ASM 344801
3. Fault Confirmation
Subtask 34-48-00-710-056-B
A. Test
   (1) Do the operational test of Enhanced GPWS ground self-test function AMM 34-48-00-710-001.
   (2) Make sure that the FAULT legend of the GPWS/SYS pushbutton switch comes on.
4. Fault Isolation
Subtask 34-48-00-810-068-A
A. If the FAULT legend of the GPWS/SYS pushbutton switch does not come on:
  • on the panel 25VU, set the INT LT/ANN LT switch to TEST and do a check to see if the FAULT legend comes on.
   (1) If the FAULT legend does not come on:
     (a) If the fault continues:
  • do a check and repair the wiring of the GPWS/SYS pushbutton switch (9WZ) from pin A/7 to annunciator light test and interface board (4LP) pin A/22 ASM 344801.
   (2) If the FAULT legend comes on:
     (a) If the fault continues:
  • do a check of the wiring of the GPWS/SYS pushbutton switch (9WZ):
    . pin A/C3 to GPWC (1WZ) pin AB/7C
    . pin A/C2 to annunciator light test and interface board (4LP) pin A/23
    ASM 344801.
       1 If there is no continuity:
  • repair the above wiring.
       2 If there is continuity:
  • do a check of the wiring of the annunciator light test and interface board (4LP):
    . pin A/24 to pin A/39
    . pin A/40 to pin A/20
    . pin A/21 to the circuit breaker (2WZ)
    ASM 344801.
         a If there is no continuity:
  • repair the above wiring.
         b If there is continuity:
  • replace the C/B-EIS/GPWS/28VDC [2WZ] .
Subtask 34-48-00-710-057-A
B. Do the test given in Para. 3.
5. Close-up
Subtask 34-48-00-860-052-A
A. Put the aircraft back to its initial configuration.
   (1) On the panel 25VU, set the INT LT/ANN LT switch to BRT.
[Rev.8 from Aug 2018] 2026.04.04 04:33:15 UTC
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