DOC AIRBUS | TSM A320FNAI Fault Light P/B Fault on EIU-1
TASK 73-25-00-810-A89-A
NAI Fault Light P/B Fault on EIU-1
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
3. Fault Confirmation
Subtask 73-25-00-710-528-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-810-390-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-860-134-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:36:48 UTC
NAI Fault Light P/B Fault on EIU-1
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AWM 302101 | |
| AMM 33-14-33-000-001 | Removal of the Annunciator-Light Test and Interface-Board |
| AMM 33-14-33-400-001 | Installation of the Annunciator-Light Test and Interface-Board |
| AWM 732501 | |
| 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) |
| AMM 73-25-34-860-803 | Engine Interface Unit (EIU) DISCRETE OUTPUTS Simulation |
Subtask 73-25-00-710-528-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 73-25-00-810-390-A ** ON A/C NOT FOR ALL
A. If there is confirmation of the fault:
(1) Remove the board (4LP) AMM 33-14-33-000-001.
(2) On the MCDU, simulate the Discrete Output (DSO) 7:
(a) Push the adjacent button to DSO 7 to have the status equal to 1 AMM 73-25-34-860-803.
(b) On the ANN LT TEST UNIT panel 70VU, tray at connector (A), do a check for ground at contact 27 AWM 732501.
1 Stop the simulation of DSO 7 AMM 73-25-34-860-803.
(3) If there is no 28VDC, do a check of wiring between contact 27 and contact 1F at EIU-1 (1KS1) connector (AB) AWM 302101 for:
(a) Continuity (Less than 5 ohms resistance)
(b) Short to ground.
1 If you find damage, repair or replace wiring AWM 302101.
2 If you find no damage:
a Replace EIU-1 [1KS1] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
3 Install the board (4LP) AMM 33-14-33-400-001.
4 Do the test given in Para. 3.
(4) If there is ground at contacts 27 or if the fault continues:
(a) Replace BOARD-ANN LT TEST & INTFC [4LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.
(b) Do the test given in Para. 3.
(5) If the fault continues:
(a) Replace EIU-1 [1KS1] 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 board (4LP) AMM 33-14-33-000-001.
(2) On the MCDU, simulate the Discrete Output (DSO) 7:
(a) Push the adjacent button to DSO 7 to have the status equal to 1 AMM 73-25-34-860-803.
(b) On the ANN LT TEST UNIT panel 70VU, tray at connector (A), do a check for ground at contact 27 AWM 732501.
1 Stop the simulation of DSO 7 AMM 73-25-34-860-803.
(3) If there is no 28VDC, do a check of wiring between contact 27 and contact 1F at EIU-1 (1KS1) connector (AB) AWM 302101 for:
(a) Continuity (Less than 5 ohms resistance)
(b) Short to ground.
1 If you find damage, repair or replace wiring AWM 302101.
2 If you find no damage:
a Replace EIU-1 [1KS1] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
3 Install the board (4LP) AMM 33-14-33-400-001.
4 Do the test given in Para. 3.
(4) If there is ground at contacts 27 or if the fault continues:
(a) Replace BOARD-ANN LT TEST & INTFC [4LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.
(b) Do the test given in Para. 3.
(5) If the fault continues:
(a) Replace EIU-1 [1KS1] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(b) Do the test given in Para. 3.
Subtask 73-25-00-860-134-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.