Inhibition of All Modes Inoperative or Permanent

TASK 34-48-00-810-820-A
Inhibition of All Modes Inoperative or Permanent

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-53-34-000-001	Removal of the Flight Warning Computer (FWC)
AMM 31-53-34-400-001	Installation of the Flight Warning Computer (FWC)
AMM 33-10-00-000-002	Removal of the Bulbs and the Body of a Pushbutton Switch in the Cockpit
AMM 33-10-00-400-002	Installation of the Bulbs and the Body of a Pushbutton Switch in the Cockpit
AMM 34-48-00-710-003	Operational Test of the STATUS/HISTORY
ASM 344801
AMM 34-48-34-000-001	Removal of the GPWC
AMM 34-48-34-400-001	Installation of the GPWC

3. Fault Confirmation
Subtask 34-48-00-710-063-A ** ON A/C NOT FOR ALL

A. Test
(1) If inhibition of all modes was inoperative, you cannot confirm this fault on the ground.
(2) If the "Mode inhibit" was permanent:

do the operational test of the STATUS/HISTORY AMM 34-48-00-710-003: the message "EXTERNAL GPWC INHIBIT" should not be present.

4. Fault Isolation
Subtask 34-48-00-810-072-A ** ON A/C NOT FOR ALL

A. If inhibition of all modes is inoperative:

do a check of the wiring of the GPWS/SYS pushbutton switch (9WZ):
. pin A/B3 to the ground point
. pin A/B1 to GPWC (1WZ) pin AB/7D
ASM 344801.

(1) If there is no continuity:

(2) If there is continuity:

(a) If the fault continues:

Subtask 34-48-00-810-095-A ** ON A/C NOT FOR ALL

B. If inhibition of all modes is permanent:

do a check of the wiring of the GPWS/SYS pushbutton switch (9WZ):
. pin A/B3 to the ground point
. pin A/B1 to GPWC (1WZ) pin AB/7D
ASM 344801.

(1) If there is no continuity:

(2) If there is continuity:

(a) If there is a short to ground:

(b) If there is no short to ground:

1 If the fault continues:

[Rev.8 from Aug 2018] 2026.04.04 04:33:15 UTC