DOC AIRBUS | TSM A320FGCU-1 Bus Fault on EIU-2
TASK 73-25-01-810-828-A
GCU-1 Bus Fault on EIU-2
1. Possible Causes
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 73-25-01-710-077-A ** ON A/C NOT FOR ALL
Subtask 73-25-01-810-085-A ** ON A/C NOT FOR ALL
Subtask 73-25-01-860-077-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:36:56 UTC
GCU-1 Bus Fault on EIU-2
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 24-22-34-000-001 | Removal of the GCU-1(2) |
| AMM 24-22-34-400-001 | Installation of the GCU-1(2) |
| AWM 315419 | |
| 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 732558 |
Subtask 73-25-01-710-077-A ** ON A/C NOT FOR ALL
A. Do the operational test of the Engine Interface Unit (EIU) with the Centralized Fault Display System (CFDS) to confirm this fault AMM 73-25-34-710-802.
4. Fault IsolationSubtask 73-25-01-810-085-A ** ON A/C NOT FOR ALL
A. If there is confirmation of the fault:
(1) Remove the EIU-2 (1KS2) AMM 73-25-34-000-802.
(2) Remove the Generator Control Unit (GCU) 1 (1XU1) AMM 24-22-34-400-001.
(3) Use a MULTIMETER - STANDARD to do a test of the EIU-2 (1KS2)/GCU-1 (1XU1) circuits in the harness AWM 732558 and AWM 315419. Refer to Table 201. Look for:
(a) Wire-to-wire shorts
(b) Shorts to ground
(c) Continuity (less than 5 ohms resistance).
Table 201: EIU-2/GCU-1 Connector Contacts
(4) If a problem is found, repair or replace the wiring AWM 732558 and AWM 315419.
(a) Install EIU-2 (1KS2) AMM 73-25-34-400-802.
(b) Install GCU-1 (1XU1) AMM 24-22-34-400-001.
(c) Do the test given in Para. 3.
(5) If no problem is found or if fault continues:
(a) Replace GCU-1 [1XU1] AMM 24-22-34-000-001 and AMM 24-22-34-400-001.
(b) Do the test given in Para. 3.
(6) If no problem is found or if fault continues:
(a) Replace EIU-2 [1KS2] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(b) Do the test given in Para. 3.
5. Close-up(1) Remove the EIU-2 (1KS2) AMM 73-25-34-000-802.
(2) Remove the Generator Control Unit (GCU) 1 (1XU1) AMM 24-22-34-400-001.
(3) Use a MULTIMETER - STANDARD to do a test of the EIU-2 (1KS2)/GCU-1 (1XU1) circuits in the harness AWM 732558 and AWM 315419. Refer to Table 201. Look for:
(a) Wire-to-wire shorts
(b) Shorts to ground
(c) Continuity (less than 5 ohms resistance).
NOTE: A short to ground is found when the resistance is less than 100 000 (100K) ohms.
Table 201: EIU-2/GCU-1 Connector Contacts
| GCU-1 (1XU1) Connector AA Contacts | EIU-2 (1KS2) Connector AA Contacts |
|---|---|
| 8F | 14G |
| 7F | 15G |
(a) Install EIU-2 (1KS2) AMM 73-25-34-400-802.
(b) Install GCU-1 (1XU1) AMM 24-22-34-400-001.
(c) Do the test given in Para. 3.
(5) If no problem is found or if fault continues:
(a) Replace GCU-1 [1XU1] AMM 24-22-34-000-001 and AMM 24-22-34-400-001.
(b) Do the test given in Para. 3.
(6) If no problem is found or if fault continues:
(a) Replace EIU-2 [1KS2] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(b) Do the test given in Para. 3.
Subtask 73-25-01-860-077-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.