Permanent Display of Terrain Data on F/O ND

TASK 34-48-00-810-835-A
Permanent Display of Terrain Data on F/O ND

1. Possible Causes

GPWC [1WZ]
P/BSW-TERR ON ND,F/O [30WZ2]
wiring of the TERRAIN POP-UP F/O discrete between the GPWC (1WZ) and the TERR ON ND, F/O pushbutton switch (30WZ2)

2. Job Set-up Information
A. Referenced Information

3. Fault Confirmation
Subtask 34-48-00-740-082-A

A. Test
(1) Do the BITE test of the Enhanced GPWS AMM 34-48-00-740-002.

4. Fault Isolation
Subtask 34-48-00-810-099-A

A. If the BITE test gives the maintenance message:
FO TERR ON ND PB SW (30WZ2)/GPWC (1WZ)

on the LDG GEAR CTL & IND PNL (402VU), make sure that the TERR ON ND, F/O pushbutton switch (30WZ2) is not pushed (the ON legend is off)
do a check for ground at pin AA/1B of the GPWC ASM 344802.

(1) If there is no ground:

(2) If there is ground:

(a) If the fault continues:

do a check and repair the wiring of the TERRAIN POP-UP F/O discrete between the GPWC (1WZ) and the TERR ON ND, F/O pushbutton switch (30WZ2): for pin AA/1B of the GPWC ASM 344802.

Subtask 34-48-00-740-083-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:17 UTC