Loss of the LGCIU1 Data Input to the ATC/Mode S Transponder 1

TASK 34-52-00-810-827-A
Loss of the LGCIU1 Data Input to the ATC/Mode S Transponder 1

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 32-31-71-000-001	Removal of the LGCIU
AMM 32-31-71-400-001	Installation of the LGCIU
AMM 34-52-00-740-004	BITE Test of the ATC
ASM 345201
AMM 34-52-12-000-001	Removal of the ATC/TCAS Control Unit
AMM 34-52-12-400-001	Installation of the ATC/TCAS Control Unit
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 34-52-00-740-094-A

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

4. Fault Isolation
Subtask 34-52-00-810-082-A

A. If the test gives the maintenance messages LGCIU1 (5GA1)/ATC1 (1SH1):

(1) If the fault continues:

(2) If the fault continues:

do a check and repair the wiring between the LGCIU1 and the ATC/TCAS control unit ASM 345201.

(3) If the fault continues:

(4) If the fault continues:

do a check and repair the wiring between the ATC/TCAS control unit and the ATC/Mode S transponder 1 for the Air/Ground Logic Input 1 discrete signal ASM 345201.

Subtask 34-52-00-740-095-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:24 UTC