DOC AIRBUS | TSM A320FRight Hand Upper Locking Feedback Actuator Proximity Switch Signal Failure on Channel B
TASK 78-31-00-810-948-A
Right Hand Upper Locking Feedback Actuator Proximity Switch Signal Failure on Channel B
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 78-31-00-710-263-A ** ON A/C NOT FOR ALL
Subtask 78-31-00-860-057-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:41:32 UTC
Right Hand Upper Locking Feedback Actuator Proximity Switch Signal Failure on Channel B
1. Possible Causes
- R UPPER ACTUATOR [3042KM1]
- HARNESS - RIGHT TRAS [4132KS]
- HARNESS - PYLON T/R [4130KS]
- EEC WIRING HARNESS WF07 [4093KS]
- PROX SENSOR-R T/R UPPER PRIMARY LOCK, CHAN B [4041KS]
[4000KS]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 71-00-00-810-843-A | Nacelle Component and Harness 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 715136 | |
| AWM 715179 | |
| AMM 73-21-01-000-801 | Removal of the Electronic Engine Control (EEC) |
| AMM 73-21-01-400-801 | Installation of the Electronic Engine Control (EEC) |
| AMM 73-21-67-000-801 | Removal of the Electronic Engine Control (EEC) Wiring Harness (WF07) |
| AMM 73-21-67-400-801 | Installation of the Electronic Engine Control (EEC) Wiring Harness (WF07) |
| AMM 78-31-00-210-802 | General Visual Inspection (GVI) of the Proximity Sensor Targets |
| AMM 78-31-00-710-805 | Operational Test of Thrust Reverser with MCDU |
| AMM 78-31-04-000-801 | Removal of the TRAS Locking-Feedback Actuator |
| AMM 78-31-04-400-801 | Installation of the TRAS Locking-Feedback Actuator |
| AMM 78-31-20-000-801 | Removal of the TRAS Actuator Proximity-Sensors |
| AMM 78-31-20-400-801 | Installation of the TRAS Actuator Proximity-Sensors |
| AMM 78-31-61-000-812 | Removal of the Right TRAS Monitoring Harness |
| AMM 78-31-61-000-813 | Removal of the Pylon TRAS Monitoring Harness |
| AMM 78-31-61-400-812 | Installation of the Right TRAS Monitoring Harness |
| AMM 78-31-61-400-813 | Installation of the Pylon TRAS Monitoring Harness |
Subtask 78-31-00-710-263-A ** ON A/C NOT FOR ALL
A. Do the operational test of the thrust reverser with the MCDU to confirm this fault AMM 78-31-00-710-805.
(1) If the maintenance message does not come back, troubleshoot as described in the nacelle component and harness troubleshooting procedure for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-843).
(a) Monitor the engine reoccurring maintenance message.
(2) If the maintenance message comes back (hard fault), go to the Para. Fault Isolation.
4. Fault Isolation(1) If the maintenance message does not come back, troubleshoot as described in the nacelle component and harness troubleshooting procedure for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-843).
(a) Monitor the engine 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.
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 78-31-00-810-292-A ** ON A/C NOT FOR ALL A. If there is confirmation of the fault:
(1) Get access to the Right Hand Upper Locking Feedback Actuator and EEC:
(a) Open the fan cowl doors AMM 71-13-00-010-802.
(2) On Actuator, at proximity sensor (4041KS), make sure that the target is not missing and do a visual inspection of the target for bend, breakage or damage AMM 78-31-00-210-802.
(a) If you find a bend, breakage or other damage, or if the target is missing:
1 Replace R UPPER ACTUATOR [3042KM1] AMM 78-31-04-000-801 and AMM 78-31-04-400-801.
2 Do the test given in Para. 3.
(3) If you find no damage or if the fault continues:
(a) Check for the correct engagement of connector (4041KS-A) and proximity sensor (4041KS):
1 Repair as necessary.
2 Do the test given in Para. 3.
(4) If the check is OK or if the fault continues, disconnect connector (4041KS-A) and do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(a) If you find damage, replace HARNESS - RIGHT TRAS [4132KS] AMM 78-31-61-000-812 and AMM 78-31-61-400-812.
(b) Reconnect connector (4041KS-A).
(c) Do the test given in Para. 3.
(5) If you find no damage or if the fault continues, disconnect connector (4054VC-A) AWM 715179.
(a) Do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(b) Do a continuity check (less than 5 ohms) between the pins of connectors (4041KS-A) and (4055VC) as follows:
(d) If you find a fault:
1 Replace HARNESS - RIGHT TRAS [4132KS] AMM 78-31-61-000-812 and AMM 78-31-61-400-812.
2 Reconnect all connectors.
3 Do the test given in Para. 3.
(6) If you find no damage or if the fault continues, disconnect connector (494VC-A) AWM 715179.
(a) Do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(b) Do a continuity check (less than 5 ohms) between the pins of connectors (4055VC-A) and (494VC) as follows:
(d) If you find a fault:
1 Replace HARNESS - PYLON T/R [4130KS] AMM 78-31-61-000-813 and AMM 78-31-61-400-813.
2 Do the test given in Para. 3.
(7) If you find no damage or if the fault continues, disconnect connector P7 from EEC AWM 715136.
(a) Do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(b) Do a continuity check (less than 5 ohms) between the pins of connectors P8 and (494VC-A) as follows:
(d) If you find a fault:
1 Replace EEC WIRING HARNESS WF07 [4093KS] AMM 73-21-67-000-801 and AMM 73-21-67-400-801.
2 Reconnect all connectors.
3 Do the test given in Para. 3.
(8) If you find no fault or if the fault continues:
(a) Replace PROX SENSOR-R T/R UPPER PRIMARY LOCK, CHAN B [4041KS] AMM 78-31-20-000-801 and AMM 78-31-20-400-801.
(b) Do the test given in Para. 3.
(9) If you find no fault or if the fault continues, replace
5. Close-up(1) Get access to the Right Hand Upper Locking Feedback Actuator and EEC:
(a) Open the fan cowl doors AMM 71-13-00-010-802.
(2) On Actuator, at proximity sensor (4041KS), make sure that the target is not missing and do a visual inspection of the target for bend, breakage or damage AMM 78-31-00-210-802.
(a) If you find a bend, breakage or other damage, or if the target is missing:
1 Replace R UPPER ACTUATOR [3042KM1] AMM 78-31-04-000-801 and AMM 78-31-04-400-801.
2 Do the test given in Para. 3.
(3) If you find no damage or if the fault continues:
(a) Check for the correct engagement of connector (4041KS-A) and proximity sensor (4041KS):
1 Repair as necessary.
2 Do the test given in Para. 3.
(4) If the check is OK or if the fault continues, disconnect connector (4041KS-A) and do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(a) If you find damage, replace HARNESS - RIGHT TRAS [4132KS] AMM 78-31-61-000-812 and AMM 78-31-61-400-812.
(b) Reconnect connector (4041KS-A).
(c) Do the test given in Para. 3.
(5) If you find no damage or if the fault continues, disconnect connector (4054VC-A) AWM 715179.
(a) Do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(b) Do a continuity check (less than 5 ohms) between the pins of connectors (4041KS-A) and (4055VC) as follows:
- Pin 2 and pin 4
- Pin 5 and pin 13
- Pin 3 and pin 14.
(d) If you find a fault:
1 Replace HARNESS - RIGHT TRAS [4132KS] AMM 78-31-61-000-812 and AMM 78-31-61-400-812.
2 Reconnect all connectors.
3 Do the test given in Para. 3.
(6) If you find no damage or if the fault continues, disconnect connector (494VC-A) AWM 715179.
(a) Do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(b) Do a continuity check (less than 5 ohms) between the pins of connectors (4055VC-A) and (494VC) as follows:
- Pin 4 and pin 32
- Pin 13 and pin 14
- Pin 14 and pin 31.
(d) If you find a fault:
1 Replace HARNESS - PYLON T/R [4130KS] AMM 78-31-61-000-813 and AMM 78-31-61-400-813.
2 Do the test given in Para. 3.
(7) If you find no damage or if the fault continues, disconnect connector P7 from EEC AWM 715136.
(a) Do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(b) Do a continuity check (less than 5 ohms) between the pins of connectors P8 and (494VC-A) as follows:
- Pin s and pin 32
- Pin r and pin 14
- Pin q and pin 31.
(d) If you find a fault:
1 Replace EEC WIRING HARNESS WF07 [4093KS] AMM 73-21-67-000-801 and AMM 73-21-67-400-801.
2 Reconnect all connectors.
3 Do the test given in Para. 3.
(8) If you find no fault or if the fault continues:
(a) Replace PROX SENSOR-R T/R UPPER PRIMARY LOCK, CHAN B [4041KS] AMM 78-31-20-000-801 and AMM 78-31-20-400-801.
(b) Do the test given in Para. 3.
(9) If you find no fault or if the fault continues, replace
Subtask 78-31-00-860-057-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.