Loss of the Output Bus from the CSAS to the CFDIU

TASK 31-32-00-810-943-A
Loss of the Output Bus from the CSAS to the CFDIU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 21-58-34-000-001	Removal of the CSAS Control Unit
AMM 21-58-34-400-001	Installation of the CSAS Control Unit
AMM 31-32-00-740-009	Read the AVIONICS STATUS on the MCDU
ASM 313206
AMM 31-32-34-000-001	Removal of the CFDIU
AMM 31-32-34-400-001	Installation of the CFDIU

3. Fault Confirmation
Subtask 31-32-00-865-179-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
122VU	CSAS / CTLR	1HW	U17

Subtask 31-32-00-740-315-A ** ON A/C NOT FOR ALL

B. Read the AVIONICS STATUS on the MCDU AMM 31-32-00-740-009.

4. Fault Isolation
Subtask 31-32-00-810-197-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message NO CSAS DATA:

(1) If the fault continues:

(a) If the fault continues:

Do a check and repair the wiring from the CFDIU (1TW) pins AB/13A, 13B to the CSAS CONTROL UNIT (100HW) ASM 313206.

Subtask 31-32-00-740-316-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:29:59 UTC