Loss of the LGCIU2 Data Input to the ATC/Mode S Transponder 2
TASK 34-52-00-810-830-A
Loss of the LGCIU2 Data Input to the ATC/Mode S Transponder 2
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 34-52-00-740-100-A 4. Fault Isolation
Subtask 34-52-00-810-085-A
[Rev.8 from Aug 2018]
2026.04.04 04:33:24 UTC
Loss of the LGCIU2 Data Input to the ATC/Mode S Transponder 2
1. Possible Causes
- LGCIU-2 [5GA2]
- CTL UNIT-ATC/TCAS [3SH]
wiring between the LGCIU2 and the ATC/TCAS control unit - XPDR-ATC/MODE S, 2 [1SH2]
wiring between the ATC/TCAS control unit and the ATC/Mode S transponder 2
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 |
Subtask 34-52-00-740-100-A 4. Fault Isolation
Subtask 34-52-00-810-085-A
A. If the test gives the maintenance message LGCIU2 (5GA2)/ATC2 (1SH2)
Subtask 34-52-00-740-101-A - replace the LGCIU-2 [5GA2] AMM 32-31-71-000-001 and AMM 32-31-71-400-001.
- replace the CTL UNIT-ATC/TCAS [3SH] AMM 34-52-12-000-001 and AMM 34-52-12-400-001.
- do a check and repair the
wiring between the LGCIU2 and the ATC/TCAS control unit ASM 345201.
- replace the XPDR-ATC/MODE S, 2 [1SH2] AMM 34-52-33-000-001 and AMM 34-52-33-400-001.
- do a check and repair the
wiring between the ATC/TCAS control unit and the ATC/Mode S transponder 2 for the Air/Ground Logic Input 2 discrete signal ASM 345201.
B. Do the test given in Para. 3.