Loss of the CFDIU Input Data to the ATC/MODE S Transponder 1

TASK 34-52-00-810-809-A
Loss of the CFDIU Input Data to the ATC/MODE S Transponder 1

1. Possible Causes

CFDIU [1TW]
XPDR-ATC/MODE S, 1 [1SH1]
wiring of the MAINTENANCE DATA INPUT bus from the CFDIU (1TW) to the ATC/Mode S transponder 1 (1SH1)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-32-34-000-001	Removal of the CFDIU
AMM 31-32-34-400-001	Installation of the CFDIU
AMM 34-52-00-740-004	BITE Test of the ATC
ASM 345201
AMM 34-52-33-000-001	Removal of the ATC/Mode S Transponder
AMM 34-52-33-400-001	Installation of the ATC/Mode S Transponder

3. Fault Confirmation
Subtask 34-52-00-740-066-A

A. Test
(1) Do the BITE test of the ATC AMM 34-52-00-740-004.

4. Fault Isolation
Subtask 34-52-00-810-060-B

A. If the BITE test gives the maintenance message CFDIU (1TW) / ATC1 (1SH1) :

(1) If the fault continues:

(a) If the fault continues :

do a check and repair the wiring of the MAINTENANCE DATA INPUT bus from the CFDIU (1TW) to the ATC/Mode S transponder 1 (1SH1) ASM 345201.

Subtask 34-52-00-740-067-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:23 UTC