DOC AIRBUS | TSM A320FTR ICV 28 VDC Failure on Channel A
TASK 73-25-00-810-996-A
TR ICV 28 VDC Failure on Channel A
1. Possible Causes
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 73-25-00-710-431-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-860-062-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:36:24 UTC
TR ICV 28 VDC Failure on Channel A
1. Possible Causes
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | MULTIMETER - STANDARD |
| No specific | 1 | PLIERS - JAWED, SOFT |
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 71-00-00-810-834-A | General Troubleshooting Guidelines for Additional Troubleshooting Information |
| TSM TASK 71-00-00-810-835-A | Component and Harness Intermittent Troubleshooting Procedure for Guidance Troubleshooting Intermittent Faults |
| AMM 71-13-00-010-802 | Opening of the Fan Cowl Doors |
| AMM 71-13-00-410-802 | Closing of the Fan Cowl Doors |
| AWM 715135 | |
| AMM 73-21-62-000-802 | Removal of the EEC Wiring Harness (WF02) |
| AMM 73-21-62-400-802 | Installation of the EEC Wiring Harness (WF02) |
| 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 73-25-34-860-806 | Engine Interface Unit (EIU) DISCRETE INPUTS Menu Data Status |
| AMM 78-31-00-710-805 | Operational Test of Thrust Reverser with MCDU |
| AWM 783604 | |
| AWM 783605 |
Subtask 73-25-00-710-431-A ** ON A/C NOT FOR ALL
A. Do the operational test of thrust reverser to confirm this fault AMM 78-31-00-710-805.
(a) If no problems are found, return the engine to service. Monitor the engine for reoccurring maintenance message.
(2) If the maintenance message comes back (hard fault), go to the Para. Fault Isolation.
4. Fault IsolationNOTE: The Electronic Engine Control (EEC) has detected a TR ICV 28 VDC for channel A when no commanded.
(1) If the maintenance message does not come back, examine the harness and electrical connectors as described in the component and harness intermittent fault isolation procedure (Ref. TSM TASK 71-00-00-810-835). - Refer to the general troubleshooting guidelines for additional troubleshooting information (Ref. TSM TASK 71-00-00-810-834).
- Refer to the component and harness intermittent troubleshooting procedure for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-835).
(a) If no problems are found, return the engine to service. Monitor the engine for reoccurring maintenance message.
(2) If the maintenance message comes back (hard fault), go to the Para. Fault Isolation.
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.
WARNING:
REFER TO THE MSDS FOR ALL MATERIAL USED AND THE MANUFACTURER'S SAFETY INSTRUCTIONS FOR ALL EQUIPMENT USED. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.
CAUTION:
MAKE SURE YOU REMOVE ELECTRICAL POWER FROM THE EEC BEFORE YOU REMOVE THE ELECTRICAL CONNECTORS. IF YOU DO NOT OBEY THIS INSTRUCTION, DAMAGE TO THE EEC CAN OCCUR.
Subtask 73-25-00-810-255-A ** ON A/C NOT FOR ALL A. If there is confirmation of the fault:
(1) Make sure that the throttle control lever is in forward idle position.
(2) Check that the status of TLA < 3 DEG is equal to 0 AMM 73-25-34-860-806.
(a) If the status is correct, go to the Para. 4.A.(3).
(b) If the status is not correct, troubleshoot as per EIU-1(2) TLA REVERSE LEVER POSITION FAULT.
(c) Do the test given in Para. 3.
(d) If the fault continues:
1 Go to the Para. 4.A.(3).
(3) Do the operational test of the Engine Interface Unit (EIU) with the Centralized Fault Display System (CFDS) AMM 73-25-34-710-802.
(a) Test EIU-1 for fault on ENG 1.
(b) Test EIU-2 for fault on ENG 2.
(4) If any maintenance message relative to REVERSER POWER SUPPLY RELAY FAULT comes on:
(a) Troubleshoot it and replace EIU-1 [1KS1] if the fault is on ENG 1 or EIU-2 [1KS2] if the fault is on ENG 2 AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(b) Do the test given in Para. 3.
(5) If no messages come on or the fault continues:
(a) Open the fan cowl doors AMM 71-13-00-010-802.
(6) Examine the WF02 (4218KS) harness, connector P1 (4000KS-P1) - EEC (4000KS) and connector P402 (402VC-A) - pylon junction box, for problems which are possible between the EEC (4000KS) and the pylon junction box.
(a) Inspect for harness damage.
(b) Inspect for loose or damaged connectors.
1 Replace HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802.
2 Do the test given in Para. 3.
(7) If no problems are found with the harness, use a PLIERS - JAWED, SOFT to disconnect the electrical connector P1 (4000KS-P1) from the EEC (4000KS) and connector P402 (402VC-A) from the pylon junction box.
(a) Examine the pins and sockets (contacts) for alignment and damage. Look for contacts pushed rearward into the connector face. Replace parts as necessary.
(b) Reconnect the electrical connector P1 (4000KS-P1) to the EEC (4000KS) and connector P402 (402VC-A) to the pylon junction box.
(c) Do the test given in Para. 3.
(8) If the fault continues:
(a) Disconnect the electrical connector P1 (4000KS-P1) from the EEC (4000KS) and connector P402 (402VC-A) from the pylon junction box. Use a MULTIMETER - STANDARD to test the aircraft 28 VDC circuit in the harness. Refer to Table 1 and AWM 715135 P0001. Look for:
1 Wire-to-wire shorts
Table 1: Aircraft 28 VDC Channel A Connector Contacts
(b) If a problem is found with the harness or connectors:
1 Replace HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802.
2 Do the test given in Para. 3.
(9) If no problems with the harness are found or the fault continues:
(a) Check the aircraft wiring for AWM 715135 P0001 and AWM 783605 for ENG 1 fault and AWM 783604 for ENG 2 fault. Look for:
1 Wire-to-wire shorts:
and
(b) Repair or replace the Aircraft wiring as necessary.
(c) Do the test given in Para. 3.
5. Close-up(1) Make sure that the throttle control lever is in forward idle position.
(2) Check that the status of TLA < 3 DEG is equal to 0 AMM 73-25-34-860-806.
(a) If the status is correct, go to the Para. 4.A.(3).
(b) If the status is not correct, troubleshoot as per EIU-1(2) TLA REVERSE LEVER POSITION FAULT.
(c) Do the test given in Para. 3.
(d) If the fault continues:
1 Go to the Para. 4.A.(3).
(3) Do the operational test of the Engine Interface Unit (EIU) with the Centralized Fault Display System (CFDS) AMM 73-25-34-710-802.
(a) Test EIU-1 for fault on ENG 1.
(b) Test EIU-2 for fault on ENG 2.
(4) If any maintenance message relative to REVERSER POWER SUPPLY RELAY FAULT comes on:
(a) Troubleshoot it and replace EIU-1 [1KS1] if the fault is on ENG 1 or EIU-2 [1KS2] if the fault is on ENG 2 AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(b) Do the test given in Para. 3.
(5) If no messages come on or the fault continues:
(a) Open the fan cowl doors AMM 71-13-00-010-802.
(6) Examine the WF02 (4218KS) harness, connector P1 (4000KS-P1) - EEC (4000KS) and connector P402 (402VC-A) - pylon junction box, for problems which are possible between the EEC (4000KS) and the pylon junction box.
(a) Inspect for harness damage.
(b) Inspect for loose or damaged connectors.
NOTE: Loose connectors must be disconnected and examined for further wear or damage.
(c) If a problem is found with the harness or connectors: 1 Replace HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802.
2 Do the test given in Para. 3.
(7) If no problems are found with the harness, use a PLIERS - JAWED, SOFT to disconnect the electrical connector P1 (4000KS-P1) from the EEC (4000KS) and connector P402 (402VC-A) from the pylon junction box.
(a) Examine the pins and sockets (contacts) for alignment and damage. Look for contacts pushed rearward into the connector face. Replace parts as necessary.
(b) Reconnect the electrical connector P1 (4000KS-P1) to the EEC (4000KS) and connector P402 (402VC-A) to the pylon junction box.
(c) Do the test given in Para. 3.
(8) If the fault continues:
(a) Disconnect the electrical connector P1 (4000KS-P1) from the EEC (4000KS) and connector P402 (402VC-A) from the pylon junction box. Use a MULTIMETER - STANDARD to test the aircraft 28 VDC circuit in the harness. Refer to Table 1 and AWM 715135 P0001. Look for:
1 Wire-to-wire shorts
Table 1: Aircraft 28 VDC Channel A Connector Contacts
| WF02 (4218KS) Harness P1(4000KS-P1) EEC (4000KS) Connector Contacts | WF02 (4218KS) Harness P402(402VC-A) Connector Contacts |
|---|---|
| D | 15 |
1 Replace HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802.
2 Do the test given in Para. 3.
(9) If no problems with the harness are found or the fault continues:
(a) Check the aircraft wiring for AWM 715135 P0001 and AWM 783605 for ENG 1 fault and AWM 783604 for ENG 2 fault. Look for:
1 Wire-to-wire shorts:
| HCU (4310EG-A) Connector Contacts | (402VC) Connector Contacts |
|---|---|
| 3 | 15 |
and
| HCU (4310EG-A) Connector Contacts | EIU (AB) Connector Contacts |
|---|---|
| 2 | 13E |
(c) Do the test given in Para. 3.
Subtask 73-25-00-860-062-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.
(a) Close the fan cowl doors AMM 71-13-00-410-802.
(1) Make sure that the work area is clean and clear of tools and other items.
(a) Close the fan cowl doors AMM 71-13-00-410-802.