Loss of the WHC 1 Output Bus by the CFDIU

TASK 31-32-00-810-897-A
Loss of the WHC 1 Output Bus by the CFDIU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 30-42-34-000-001	Removal of the Window Heat Computer (WHC)
AMM 30-42-34-400-001	Installation of the Window Heat Computer (WHC)
AMM 31-32-00-869-002	Procedure for the Class 3 Fault Reading
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 31-32-00-865-144-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
123VU	ANTI ICE/L/WHSLD	1DG1	AF10

Subtask 31-32-00-740-240-A

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

4. Fault Isolation
Subtask 31-32-00-810-147-A

A. If the test gives the maintenance message NO WHC1 DATA:

(1) If the fault continues:

(2) If the fault continues:

do a check and repair the wiring from the CFDIU (1TW) to the WHC 1 (2DG1) from pins AA/8D, 8E to pins B/M, N ASM 313206.

Subtask 31-32-00-740-241-A

B. Do the test given in Para. 3.B.

[Rev.8 from Aug 2018] 2026.04.04 04:29:56 UTC