Loss of the BUS 1 Data from the CFDIU to the RMP 1

TASK 23-13-00-810-847-A
Loss of the BUS 1 Data from the CFDIU to the RMP 1

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-13-00-740-001	BITE Test of the Radio Management
AMM 23-13-13-000-001	Removal of the Radio Management Panel (RMP)
AMM 23-13-13-400-001	Installation of the Radio Management Panel (RMP)
ASM 313202

3. Fault Confirmation
Subtask 23-13-00-865-063-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
121VU	CFDS/CFDIU/SPLY	2TW	J18
121VU	CFDS/CFDIU/BACK/UP	8TW	J17

Subtask 23-13-00-740-120-A

B. Test
Do the BITE test of the Radio Management AMM 23-13-00-740-001.

NOTE: Do this test for the RMP 1 only.

4. Fault Isolation
Subtask 23-13-00-810-088-B

A. If the test gives the maintenance message CFDIU(1TW)/RMP1(1RG1):

replace the RMP-COM/NAV FREQ SEL, 1 [1RG1] AMM 23-13-13-000-001 and AMM 23-13-13-400-001.

(1) If the fault continues:

do a check and repair the wiring of the BUS 1 OUTPUT signal, (from RMP 1 (1RG1) pins A/A, B to the first terminal block) ASM 313202.

Subtask 23-13-00-740-121-A

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

[Rev.8 from Aug 2018] 2026.04.04 04:25:40 UTC