W DOC AIRBUS | TSM A320F

Terrain Function Not Available

TASK 34-48-00-810-832-A
Terrain Function Not Available

1. Possible Causes
  • GPWC [1WZ]
  • P/BSW-GPWS/TERR [31WZ]
  • SDAC-1 [1WV1]
  • SDAC-2 [1WV2]
  • wiring of the TERRAIN AWARNESS INHIBIT discrete between the GPWC (1WZ), the GPWS/TERR pushbutton switch (31WZ) and the SDAC-1 and SDAC-2
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
ESPM 2045110
AMM 31-55-34-000-001
Removal of the SDAC
AMM 31-55-34-400-001
Installation of the SDAC
AMM 34-48-00-740-002
BITE Test of the GPWS
ASM 344802
AMM 34-48-34-000-001
Removal of the GPWC
AMM 34-48-34-400-001
Installation of the GPWC
3. Fault Confirmation
Subtask 34-48-00-740-076-A
A. Do the BITE test of the Enhanced GPWS AMM 34-48-00-740-002.
4. Fault Isolation
Subtask 34-48-00-810-096-A
A. If the BITE test gives the maintenance message:
GPWS TERR PB SW (31WZ)/GPWC (1WZ)
  • on the GPWS section of panel 21VU, make sure that the GPWS/TERR pushbutton switch (31WZ) is not pushed (the OFF legend is off)
  • do a check for ground at pin AB/14B of the GPWC ASM 344802.
   (1) If there is no ground:
   (2) If there is ground:
     (a) If there is ground:
       1 If there is no ground:
       2 If there is ground:
         a If there is no ground:
         b If there is ground:
  • do a check and repair the wiring of the TERRAIN AWARNESS INHIBIT discrete between the GPWC (1WZ), the GPWS/TERR pushbutton switch (31WZ) and the SDAC-1 and SDAC-2: for pin AB/14B of the GPWC ASM 344802.
Subtask 34-48-00-740-077-A
B. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:33:17 UTC
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