W DOC AIRBUS | TSM A320F

Left Track Lock Proximity Switch Disagreement Failure

TASK 78-31-00-810-958-A
Left Track Lock Proximity Switch Disagreement Failure

1. Possible Causes
  • TERTIARY LOCK UNIT-TRAS, R [3022KM]
  • HARNESS - LEFT TRAS [4131KS]
  • HARNESS - PYLON T/R [4130KS]
  • EEC WIRING HARNESS WF06 [4089KS]
  • EEC WIRING HARNESS WF07 [4093KS]
  • PROX SENSOR-L T/R LOWER TERTIARY LOCK, CHAN A [4038KS]
  • PROX SENSOR-L T/R LOWER TERTIARY LOCK, CHAN B [4046KS]
  • [4000KS]
2. Job Set-up Information
 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 71-13-00-410-802
Closing of the Fan Cowl Doors
AWM 715135
AWM 715136
AWM 715178
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 73-21-66-000-802
Removal of the Electronic Engine Control (EEC) Wiring Harness (WF06)
AMM 73-21-66-400-802
Installation of the Electronic Engine Control (EEC) Wiring Harness (WF06)
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 78-31-61-000-811
Removal of the Left TRAS Monitoring Harness
AMM 78-31-61-000-813
Removal of the Pylon TRAS Monitoring Harness
AMM 78-31-61-400-811
Installation of the Left TRAS Monitoring Harness
AMM 78-31-61-400-813
Installation of the Pylon TRAS Monitoring Harness
AMM 78-36-00-010-802
Opening of the Thrust Reverser Cowl-Doors
AMM 78-37-01-000-801
Removal of the Thrust Reverser Actuator System (TRAS) Track Lock
AMM 78-37-01-400-801
Installation of the Thrust Reverser Actuator System (TRAS) Track Lock
AMM 78-37-20-000-801
Removal of the TRAS Track Lock Proximity Sensors
AMM 78-37-20-400-801
Installation of the TRAS Track Lock Proximity Sensors
3. Fault Confirmation
Subtask 78-31-00-710-273-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
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 78-31-00-810-302-A ** ON A/C NOT FOR ALL
A. If there is confirmation of the fault:
   (1) Get access to left track lock and EEC:
     (a) Open the right thrust reverser cowl door AMM 78-36-00-010-802.
   (2) On track lock, at proximity sensors (4038KS) and (4046KS), 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 TERTIARY LOCK UNIT-TRAS, R [3022KM] AMM 78-37-01-000-801 and AMM 78-37-01-400-801.
       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 connectors (4038KS-A) and (4046KS-A) :
       1 Repair as necessary.
       2 Do the test given in Para. 3.
   (4) If the check is OK or if the fault continues, disconnect connectors (4038KS-A) and (4046KS-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 - LEFT TRAS [4131KS] AMM 78-31-61-000-811 and AMM 78-31-61-400-811.
   (5) If you find no damage or if the fault continues, disconnect connectors (4052VC-A) and (4053VC-A) AWM 715178 and AWM 715179.
     (a) Do a visual inspection of the connectors for bent pins, contamination or corrosion or other signs of damage.
     (b) Do a continuity check (less than 5 ohms) between pins of connectors (4038KS-A) and (4052VC) as follows:
  • Pin 2 and pin 8
  • Pin 5 and pin 19
  • Pin 3 and pin 20.
     (c) Do a continuity check (less than 5 ohms) between the pins of connectors (4046KS-A) and (4053VC) as follows:
  • Pin 2 and pin 8
  • Pin 5 and pin 19
  • Pin 3 and pin 20.
     (d) Do a check of each wire for wire-to-wire, short circuit and short to ground.
     (e) If you find damage, replace HARNESS - LEFT TRAS [4131KS] AMM 78-31-61-000-811 and AMM 78-31-61-400-811.
       1 Reconnect all connectors.
       2 Do the test given in Para. 3.
   (6) If you find no damage or if the fault continues, disconnect connectors (491VC-A) and (494VC-A) AWM 715178 and AWM 715179.
     (a) Do a visual inspection of the connectors 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 (4052VC-A) and (491VC) as follows:
  • Pin 8 and pin 10
  • Pin 19 and pin 25
  • Pin 20 and pin 26.
     (c) Do a continuity check (less than 5 ohms) between the pins of connectors (4053VC-A) and (494VC) as follows:
  • Pin 8 and pin 10
  • Pin 19 and pin 25
  • Pin 20 and pin 26.
     (d) Do a check of each wire for wire-to-wire, short circuit and short to ground.
     (e) 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 Reconnect all connectors.
       3 Do the test given in Para. 3.
   (7) If your find no damage or if the fault continues, disconnect connectors P7 and P8 from EEC AWM 715135 and AWM 715136.
     (a) Do a visual inspection of the connectors 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 P7 and (491VC-A) as follows:
  • pin FF and pin 10
  • pin EE and pin 25
  • pin DD and pin 26.
     (c) Do a continuity check (less than 5 ohms) between the pins of connectors P8 and (494VC-A) as follows:
  • Pin FF and pin 10
  • Pin EE and pin 25
  • Pin DD and pin 26.
     (d) Do a check of each wire for wire-to-wire, short circuit and short to ground.
     (e) If you find a fault:
       1 Replace EEC WIRING HARNESS WF06 [4089KS] AMM 73-21-66-000-802 and AMM 73-21-66-400-802 and/or 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 damage or if the fault continues:
     (a) Replace PROX SENSOR-L T/R LOWER TERTIARY LOCK, CHAN A [4038KS] and PROX SENSOR-L T/R LOWER TERTIARY LOCK, CHAN B [4046KS] AMM 78-37-20-000-801 and AMM 78-37-20-400-801.
     (b) Do the test given in Para. 3.
   (9) If you find no fault or if the fault continues, replace [4000KS] AMM 73-21-01-000-801 and AMM 73-21-01-400-801.
5. Close-up
Subtask 78-31-00-860-067-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.
[Rev.8 from Aug 2018] 2026.04.04 04:38:15 UTC
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