Loss of the Output Bus from the ISIS Indicator to the CFDIU

TASK 31-32-00-810-944-A
Loss of the Output Bus from the ISIS Indicator to the CFDIU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-32-00-740-009	Read the AVIONICS STATUS on the MCDU
ASM 313205
AMM 31-32-34-000-001	Removal of the CFDIU
AMM 31-32-34-400-001	Installation of the CFDIU
AMM 34-22-25-000-001	Removal of the ISIS Indicator
AMM 34-22-25-400-001	Installation of the ISIS Indicator

3. Fault Confirmation
Subtask 31-32-00-875-050-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	NAV/STBY/INST	5FN	F12
105VU	NAV/STBY/INST/BAT	23FN	J01
122VU	LIGHTING/INSTL LT/MAIN INST/PNL AND/PED	4LF	Y04

Subtask 31-32-00-740-317-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 31-32-00-810-198-A ** ON A/C NOT FOR ALL

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

(1) If the fault continues:

(a) If the fault continues:

Do a check and repair the wiring from the CFDIU (1TW) pins AB/9H, 9J to the ISIS indicator (22FN) ASM 313205.

Subtask 31-32-00-740-318-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