Loss of the communication between BMC and CFDIU

TASK 36-11-00-810-963-A
Loss of the communication between BMC and CFDIU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-32-00-869-002	Procedure for the Class 3 Fault Reading
ASM 313204
AMM 31-32-34-000-001	Removal of the CFDIU
AMM 31-32-34-400-001	Installation of the CFDIU
ASM 361103
AMM 36-11-34-000-001	Removal of the BMC
AMM 36-11-34-400-001	Installation of the BMC

3. Fault Confirmation
Subtask 36-11-00-865-072-A ** ON A/C NOT FOR ALL

A. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR BLEED/ENG 1/CTL	3HA1	D12
49VU	AIR BLEED/ENG 1/MONG	2HA1	D11

Subtask 36-11-00-740-073-A ** ON A/C NOT FOR ALL

B. Test
On the CFDS MENU page, get access to the AVIONICS STATUS page AMM 31-32-00-869-002.

4. Fault Isolation
Subtask 36-11-00-810-267-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message: NO BMC 1 DATA:

(1) If the fault continues:

do a check and repair the wiring from the CFDIU [1TW] pins AA/7D, 7E to the first terminal block, ASM 313204.

(2) If the fault continues:

(3) If the fault continues:

do a check and repair the wiring for the ARINC 429 OUTPUT BUS from the BMC-1 [1HA1] AA/10C, 11C to the BMC 2 (1HA2) AA/1D, 2D, ASM 361103.

Subtask 36-11-00-740-074-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:51 UTC