DMU Receives No Data from the BMC 1 or BMC 2

TASK 31-36-00-810-821-A
DMU Receives No Data from the BMC 1 or BMC 2

1. Possible Causes

wiring
BMC-1 [1HA1]
BMC-2 [1HA2]
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 36-11-00-710-001	Operational Test to read the CURRENT STATUS of the Engine Bleed Air System

3. Fault Confirmation
Subtask 31-36-00-740-068-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 on the panel 121VU and 2HA1, 3HA1 on the panel 49VU and 2HA2, 3HA2 on the panel 122VU are closed during the test.

4. Fault Isolation
Subtask 31-36-00-810-061-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message:

NO BMC 1 DATA, or
NO BMC 2 DATA

(1) Do the operational test of the Bleed Monitoring Computer AMM 36-11-00-710-001.

(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 BMC-1 [1HA1] or BMC-2 [1HA2] to the DMU [1TV] ASM 313701:

BMC 1 Connector AA/10C to DMU Connector AA/1J
BMC 1 Connector AA/11C to DMU Connector AA/1K
BMC 1 Connector AA/12C to Ground
or
BMC 2 Connector AA/10C to DMU Connector AB/1J
BMC 2 Connector AA/11C to DMU Connector AB/1K
BMC 2 Connector AA/12C to Ground

(3) If the fault continues:

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

Subtask 31-36-00-740-069-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:30:02 UTC