DOC AIRBUS | TSM A320FTerrain Function Not Available
TASK 34-48-00-810-832-A
Terrain Function Not Available
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 34-48-00-740-076-A 4. Fault Isolation
Subtask 34-48-00-810-096-A
[Rev.8 from Aug 2018]
2026.04.04 04:40:26 UTC
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
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 |
Subtask 34-48-00-740-076-A 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)
Subtask 34-48-00-740-077-A 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.
- replace the GPWC [1WZ] AMM 34-48-34-000-001 and AMM 34-48-34-400-001.
- replace the P/BSW-GPWS/TERR [31WZ] ESPM 2045110.
- remove the SDAC-1 [1WV1] AMM 31-55-34-000-001
- do a check for a ground signal at pin AB/14B of the GPWC.
- install a new SDAC-1 AMM 31-55-34-400-001.
- install the SDAC-1
- remove the SDAC-2 [1WV2] AMM 31-55-34-000-001
- install a new SDAC-2 AMM 31-55-34-400-001.
- 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.
B. Do the test given in Para. 3.