Loss of Data from the VHF 1 Transceiver to the CFDIU

TASK 31-32-00-810-907-A
Loss of Data from the VHF 1 Transceiver to the CFDIU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 231201
AMM 23-12-33-000-001	Removal of the VHF Transceiver
AMM 23-12-33-400-001	Installation of the VHF Transceiver
AMM 31-32-00-869-002	Procedure for the Class 3 Fault Reading
AMM 31-32-34-000-001	Removal of the CFDIU
AMM 31-32-34-400-001	Installation of the CFDIU

3. Fault Confirmation
Subtask 31-32-00-865-149-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	COM/VHF/1	2RC1	G09
** ON A/C NOT FOR ALL
49VU	COM NAV/VHF/1	2RC1	G09

Subtask 31-32-00-740-260-A

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

4. Fault Isolation
Subtask 31-32-00-810-157-A

A. If the test gives the maintenance message NO VHF1 DATA:

(1) If the fault continues:

(2) If the fault continues:

do a check and repair the wiring from the VHF 1 transceiver (1RC1) to the CFDIU (1TW) ASM 231201.

Subtask 31-32-00-740-261-A

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

[Rev.8 from Aug 2018] 2026.04.04 04:29:57 UTC