DOC AIRBUS | TSM A320FACSC Secondary BUS Fault on EIU-2
TASK 73-25-00-810-A55-A
ACSC Secondary 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 73-25-00-710-492-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-810-336-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-860-097-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:36:30 UTC
ACSC Secondary 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 | PLIERS - JAWED, SOFT |
| REFERENCE | DESIGNATION |
|---|---|
| AWM 216110 | |
| AMM 21-61-34-000-002 | Removal of the Air-Conditioning System Controller |
| AMM 21-61-34-400-002 | Installation of the Air-Conditioning System Controller |
| AWM 732520 | |
| 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) |
Subtask 73-25-00-710-492-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 73-25-00-810-336-A ** ON A/C NOT FOR ALL
A. If there is confirmation of the fault:
(1) Remove EIU-2 [1KS2] AMM 73-25-34-000-802.
(2) Remove CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-000-002.
(3) Use a PLIERS - JAWED, SOFT to test the EIU/ACSC 2 circuits in the harness AWM 216110 and AWM 732520. Refer to Table 1. Look for:
(a) Wire-to-wire shorts
(b) Shorts to ground
(c) Continuity (less than 5 ohms resistance).
Table 1: EIU/ACSC 2 Connector Contacts
(4) If a problem is found:
(a) Repair or replace wiring AWM 216110 and AWM 732520.
(b) Install EIU-2 [1KS2] AMM 73-25-34-400-802.
(c) Install CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-400-002.
(d) Do the test given in Para. 3.
(5) If no problem is found or if fault continues:
(a) Replace CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.
(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 EIU-2 [1KS2] AMM 73-25-34-000-802.
(2) Remove CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-000-002.
(3) Use a PLIERS - JAWED, SOFT to test the EIU/ACSC 2 circuits in the harness AWM 216110 and AWM 732520. Refer to Table 1. 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).
Table 1: EIU/ACSC 2 Connector Contacts
| ACSC 2 (57HH) Connector AA Contacts | EIU-2 (1KS2) Connector AA Contacts |
|---|---|
| 7E | 3J |
| 7F | 3K |
(a) Repair or replace wiring AWM 216110 and AWM 732520.
(b) Install EIU-2 [1KS2] AMM 73-25-34-400-802.
(c) Install CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-400-002.
(d) Do the test given in Para. 3.
(5) If no problem is found or if fault continues:
(a) Replace CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.
(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 73-25-00-860-097-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.