DOC AIRBUS | TSM A320FLGCIU 1 and 2 Buses Fault on EIU-1
TASK 73-25-00-810-C65-A
LGCIU 1 and 2 Buses Fault on EIU-1
1. Possible Causes
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 73-25-00-710-713-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-810-665-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-860-310-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:36:55 UTC
LGCIU 1 and 2 Buses Fault on EIU-1
1. Possible Causes
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | MULTIMETER - STANDARD |
| REFERENCE | DESIGNATION |
|---|---|
| AMM 32-31-71-000-001 | Removal of the LGCIU |
| AMM 32-31-71-400-001 | Installation of the LGCIU |
| AWM 326105 | |
| AWM 326106 | |
| AMM 73-25-34-000-802 | Removal of the Engine Interface Unit (EIU) |
| AMM 73-25-34-400-802 | Installation of the Engine Interface Unit (EIU) |
| AMM 73-25-34-710-802 | Operational Test of the Engine Interface Unit (EIU) with the Centralized Fault Display System (CFDS) |
| AWM 732557 |
Subtask 73-25-00-710-713-A ** ON A/C NOT FOR ALL
A. Do the operational test of the Engine Interface Unit (EIU) (1KS1) with the Centralized Fault Display System (CFDS) to confirm this fault AMM 73-25-34-710-802.
4. Fault IsolationSubtask 73-25-00-810-665-A ** ON A/C NOT FOR ALL
A. Do as follows:
(1) Replace LGCIU-1 [5GA1] and LGCIU-2 [5GA2] AMM 32-31-71-000-001 and AMM 32-31-71-400-001.
(a) Do the test given in Para. 3.
(2) If the fault continues:
(a) Remove EIU-1 [1KS1] AMM 73-25-34-000-802.
(b) Remove LGCIU-1 [5GA1] and LGCIU-2 [5GA2] AMM 32-31-71-000-001.
(c) Use a MULTIMETER - STANDARD to do a test of the circuits AWM 732557, AWM 326105 and AWM 326106. Refer to Table 1 and Table 2. Look for:
1 Wire-to-wire shorts
2 Shorts to ground
3 Continuity (less than 5 ohms resistance).
Table 1: LGCIU 1 Circuit Connector Contacts
Table 2: LGCIU 2 Circuit Connector Contacts
(3) If a problem is found repair or replace wiring .
(a) Install EIU-1 [1KS1] AMM 73-25-34-400-802.
(b) Install LGCIU-1 [5GA1] and LGCIU-2 [5GA2] AMM 32-31-71-400-001.
(c) Do the test given in Para. 3.
(4) If no problem is found or if the fault continues:
(a) Replace EIU-1 [1KS1] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(b) Install LGCIU-1 [5GA1] and LGCIU-2 [5GA2] AMM 32-31-71-400-001.
(c) Do the test given in Para. 3.
5. Close-up(1) Replace LGCIU-1 [5GA1] and LGCIU-2 [5GA2] AMM 32-31-71-000-001 and AMM 32-31-71-400-001.
(a) Do the test given in Para. 3.
(2) If the fault continues:
(a) Remove EIU-1 [1KS1] AMM 73-25-34-000-802.
(b) Remove LGCIU-1 [5GA1] and LGCIU-2 [5GA2] AMM 32-31-71-000-001.
(c) Use a MULTIMETER - STANDARD to do a test of the circuits AWM 732557, AWM 326105 and AWM 326106. Refer to Table 1 and Table 2. Look for:
1 Wire-to-wire shorts
2 Shorts to ground
3 Continuity (less than 5 ohms resistance).
NOTE: A short to ground is found when the resistance is less than 100 000 (100K) ohms.
Table 1: LGCIU 1 Circuit Connector Contacts
| LGCIU 1 (5GA1) Contacts | EIU-1 (1KS1) Connector AA Contacts |
|---|---|
| 13K | 10A |
| 15K | 11A |
Table 2: LGCIU 2 Circuit Connector Contacts
| LGCIU 2 (5GA2) Contacts | EIU 1 (1KS1) Connector AA Contacts |
|---|---|
| 13J | 14A |
| 15J | 15A |
(a) Install EIU-1 [1KS1] AMM 73-25-34-400-802.
(b) Install LGCIU-1 [5GA1] and LGCIU-2 [5GA2] AMM 32-31-71-400-001.
(c) Do the test given in Para. 3.
(4) If no problem is found or if the fault continues:
(a) Replace EIU-1 [1KS1] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(b) Install LGCIU-1 [5GA1] and LGCIU-2 [5GA2] AMM 32-31-71-400-001.
(c) Do the test given in Para. 3.
Subtask 73-25-00-860-310-A ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(1) Make sure that the work area is clean and clear of tools and other items.