DMU Receives No Data from the GPWC

TASK 31-36-00-810-826-A
DMU Receives No Data from the GPWC

1. Possible Causes

wiring
GPWC [1WZ]
DMU [1TV]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-36-00-710-001	Test of the DMU
AMM 31-36-34-000-001	Removal of the Data Management Unit (DMU)
AMM 31-36-34-400-001	Installation of the Data Management Unit (DMU)
ASM 313701
AMM 34-48-00-710-001	Operational Test of GPWS Ground Self-test Function

3. Fault Confirmation
Subtask 31-36-00-740-078-A ** ON A/C NOT FOR ALL

A. Do the DMU (1TV) fault monitoring test AMM 31-36-00-710-001.

NOTE: Make sure that the circuit breakers 1TV, 2WZ, 3WZ on the panel 121VU are closed during the test.

4. Fault Isolation
Subtask 31-36-00-810-066-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message:

NO GPWS DATA

(1) Do the operational test of the Ground Proximity Warning System AMM 34-48-00-710-001.

(a) If the test gives a different maintenance message, you can find the related trouble shooting procedure in the applicable Page Block 201.

(2) If the fault continues:

do a check and repair the wiring from the GPWC [1WZ] to the DMU [1TV] ASM 313701:

GPWC Connector AB/1C to DMU Connector AA/5C
GPWC Connector AB/1D to DMU Connector AA/5D

(3) If the fault continues:

replace the DMU (1TV) AMM 31-36-34-000-001 and AMM 31-36-34-400-001.

Subtask 31-36-00-740-079-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:30:03 UTC