Loss of Data from the VHF 3 Transceiver to the CFDIU

TASK 31-32-00-810-905-A
Loss of Data from the VHF 3 Transceiver to the CFDIU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 231203
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 31-32-00-865-147-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	COM NAV/VHF/3	2RC3	L05
** ON A/C NOT FOR ALL
121VU	COM/VHF/3	2RC3	L05

Subtask 31-32-00-740-256-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 31-32-00-810-155-A

A. If the test gives the maintenance message NO VHF3 DATA:

(1) If the fault continues:

(2) If the fault continues:

do a check and repair the wiring from the VHF 3 transceiver (1RC3) to the CFDIU (1TW) ASM 231203.

Subtask 31-32-00-740-257-A

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

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