CFDIU BUS Fault on EIU-1
TASK 73-25-00-810-A56-A
CFDIU BUS 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 73-25-00-710-493-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-810-337-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-860-098-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:36:44 UTC
CFDIU BUS 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 | PLIERS - JAWED, SOFT |
| REFERENCE | DESIGNATION |
|---|---|
| AWM 313204 | |
| AWM 313217 | |
| AMM 31-32-34-000-001 | Removal of the CFDIU |
| AMM 31-32-34-400-001 | Installation of the CFDIU |
| 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 73-25-00-710-493-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 73-25-00-810-337-A ** ON A/C NOT FOR ALL
A. If there is confirmation of the fault:
(1) Remove EIU-1 [1KS1] AMM 73-25-34-000-802.
(2) Remove CFDIU [1TW] AMM 31-32-34-000-001.
(3) Use a PLIERS - JAWED, SOFT to test the EIU/CFDIU circuits in the harness AWM 313217 and AWM 313204. 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/CFDIU Connector Contacts
(4) If a problem is found:
(a) Repair or replace wiring AWM 313217 and AWM 313204.
(b) Install EIU-1 [1KS1] AMM 73-25-34-400-802.
(c) Install CFDIU [1TW] AMM 31-32-34-400-001.
(d) Do the test given in Para. 3.
(5) If no problem is found or if fault continues:
(a) Replace CFDIU [1TW] AMM 31-32-34-000-001 and AMM 31-32-34-400-001.
(b) Do the test given in Para. 3.
(6) If no problem is found or if 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 EIU-1 [1KS1] AMM 73-25-34-000-802.
(2) Remove CFDIU [1TW] AMM 31-32-34-000-001.
(3) Use a PLIERS - JAWED, SOFT to test the EIU/CFDIU circuits in the harness AWM 313217 and AWM 313204. 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/CFDIU Connector Contacts
| CFDIU (1TW) Connector AA Contacts | EIU-1 (1KS1) Connector AA Contacts |
|---|---|
| 11F | 11C |
| 11G | 12B |
(a) Repair or replace wiring AWM 313217 and AWM 313204.
(b) Install EIU-1 [1KS1] AMM 73-25-34-400-802.
(c) Install CFDIU [1TW] AMM 31-32-34-400-001.
(d) Do the test given in Para. 3.
(5) If no problem is found or if fault continues:
(a) Replace CFDIU [1TW] AMM 31-32-34-000-001 and AMM 31-32-34-400-001.
(b) Do the test given in Para. 3.
(6) If no problem is found or if 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 73-25-00-860-098-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.