Failure of the EIU on Engine 1
TASK 73-25-00-810-853-A
Failure of the EIU on Engine 1
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 73-25-00-710-154-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-865-056-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:41:01 UTC
Failure of the EIU on Engine 1
1. Possible Causes
- EIU-1 [1KS1]
- aircraft wirings
- C/B-ENGINE/1/FADEC A/AND EIU 1 [2KS1]
- C/B-ENGINE/ENG1/FADEC B/AND EIU 1 [4KS1]
- ECU [4000KS]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 73-21-60-000-001 | Removal of the Electronic Control Unit (ECU) |
| AMM 73-21-60-400-001 | Installation of the Electronic Control Unit (ECU) |
| ASM 732505 | |
| AMM 73-25-34-000-040 | Removal of the Engine Interface Unit (EIU) |
| AMM 73-25-34-400-040 | Installation of the Engine Interface Unit (EIU) |
| AMM 73-25-34-710-040 | Operational Test of the Engine Interface Unit |
| AMM 73-25-34-710-043 | Operational Test of the Engine Interface Unit |
Subtask 73-25-00-710-154-A ** ON A/C NOT FOR ALL
A. Do the operational test of the Engine Interface Unit (EIU) through the Centralized Fault Display System (CFDS) AMM 73-25-34-710-040.
Subtask 73-25-00-710-154-B ** ON A/C NOT FOR ALL A. Do the operational test of the Engine Interface Unit (EIU) through the Centralized Fault Display System (CFDS) AMM 73-25-34-710-043.
4. Fault IsolationSubtask 73-25-00-865-056-A ** ON A/C NOT FOR ALL
A. Table of the circuit breakers used in this procedure:
Subtask 73-25-00-810-102-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 49VU | ENGINE/1/FADEC A/AND EIU 1 | 2KS1 | A04 |
| 121VU | ENGINE/ENG1/FADEC B/AND EIU 1 | 4KS1 | R41 |
B. If the test gives the maintenance message EIU 1:
Subtask 73-25-00-710-155-A ** ON A/C NOT FOR ALL - do a check for 28VDC at EIU 1 (1KS1) pins AC/9, 11.
- replace the EIU-1 [1KS1] AMM 73-25-34-000-040 and AMM 73-25-34-400-040.
- do a check for open or short to ground of the aircraft wirings between the EIU 1 (1KS1) and the circuit breakers (2KS1) and (4KS1) pins AC/9, 11.
- repair the defective wiring(s)
- replace the defective C/B-ENGINE/1/FADEC A/AND EIU 1 [2KS1] or the C/B-ENGINE/ENG1/FADEC B/AND EIU 1 [4KS1] ASM 732505.
- replace the ECU [4000KS] AMM 73-21-60-000-001 and AMM 73-21-60-400-001.
C. Do the operational test of the Engine Interface Unit (EIU) through the Centralized Fault Display System (CFDS) AMM 73-25-34-710-040.
Subtask 73-25-00-710-155-B ** ON A/C NOT FOR ALL C. Do the operational test of the Engine Interface Unit (EIU) through the Centralized Fault Display System (CFDS) AMM 73-25-34-710-043.