DOC AIRBUS | TSM A320FFailure of the Thrust-Reverser Actuator Lock Indicator/Proximity Sensor on Engine 2, Channel A
1. Possible Causes
· LOCK IND/PROX SENSOR-THRUST REV LOWER L ACTUATOR ( 4007KS )
· C/B-ENGINE/ENG2/OIL/PRESS/AND REV SNSR/CHAN A ( 2EN2 )
· wiring from the lock indicator/proximity sensor (4007KS) to the EEC (4000KS)
· wiring from the lock indicator/proximity sensor (4007KS) to the C/B (2EN2)
· EEC ( 4000KS )
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
Ref. AMM 71-13-00-410-010 Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
Ref. AMM 71-50-00-210-010 Wire Harness Visual Inspection - All Power Plant Electrical Cables
Ref. AMM 71-50-00-220-010 Wire Continuity Check - All Power Plant Electrical Cables
Ref. AMM 73-22-34-000-010 Removal of the Electronic Engine Control (EEC)
Ref. AMM 73-22-34-400-010 Installation of the Electronic Engine Control (EEC)
Ref. ASM 73-25-16
Ref. AMM 78-31-00-710-041 Operational Test of the Thrust Reverser System with the CFDS
Ref. AMM 78-31-15-000-010 Removal of the Lock Indicator Proximity Sensor
Ref. AMM 78-31-15-400-010 Installation of the Lock Indicator Proximity Sensor
Ref. AMM 78-32-00-410-010 Closing of the Thrust Reverser Halves
Left Thrust Reverser Lock Indicator/Proximity Sensor SHEET 1
Figure 78(IAE)-30-00-991-00100-A / SHEET 1/1 - Left Thrust Reverser Lock Indicator/Proximity Sensor
not printed, as per printing preferences
3. Fault Confirmation
Subtask 78-30-00-710-150-A
A. Test
(1) Do the operational test of the thrust reverser system with the CFDS (through FADEC 2A and 2B
menus) Ref. AMM 78-31-00-710-041 .
4. Fault Isolation
(Ref. Fig. Left Thrust Reverser Lock Indicator/Proximity Sensor SHEET 1)
Subtask 78-30-00-810-115-A
A. If the test gives the maintenance message REV SL SENS CHA/HC/EEC 2:
· Examine the harness Ref. AMM 71-50-00-210-010 from the EEC (4000KS) to the left thrust-reverser
locking actuator Ref. ASM 73-25-16.
(1) If the fault continues:
· Replace the connector of the lock indicator/proximity sensor (4007KS).
(2) If the fault continues:
· Replace the LOCK IND/PROX SENSOR-THRUST REV LOWER L ACTUATOR ( 4007KS ) Ref.
AMM 78-31-15-000-010 and Ref. AMM 78-31-15-400-010 .
(3) If the fault continues:
· Replace the C/B-ENGINE/ENG2/OIL/PRESS/AND REV SNSR/CHAN A ( 2EN2 ) .
(4) If the fault continues:
· Do a check of the wiring from the lock indicator/proximity sensor (4007KS) to the EEC (4000KS)
pins A/B, C to pins J1/k, s Ref. ASM 73-25-16 Ref. AMM 71-50-00-220-010 .
NOTE: While performing this task, it is recommended to thoroughly shake the wiring, in order to increase
the chances to isolate a potential defect that would cause intermittent electrical issues.
(a) If there is no continuity or there is intermittent electrical issue:
· Repair the above wiring.
(b) If there is continuity and there is no intermittent electrical issue:
· Do a check of the wiring from the lock indicator/proximity sensor (4007KS) to the C/B (2EN2)
pin A/A to pin 2 Ref. ASM 73-25-16 Ref. AMM 71-50-00-220-010 .
NOTE: While performing this task, it is recommended to thoroughly shake the wiring, in order to
increase the chances to isolate a potential defect that would cause intermittent electrical
issues.
(c) If there is no continuity or there is intermittent electrical issue:
· Repair the above wiring.
(d) If the fault continues, replace the wiring from the LOCK IND/PROX SENSOR-THRUST REV
LOWER L ACTUATOR ( 4007KS ) to the EEC ( 4000KS ) pins A/B, C to pin J7/k,s.
(e) If the fault continues, replace the wiring from the LOCK IND/PROX SENSOR-THRUST REV
LOWER L ACTUATOR ( 4007KS ) to the C/B-ENGINE/ENG2/OIL/PRESS/AND REV SNSR/
CHAN A ( 2EN2 ) pin A/A to pin2.
(f) If there is continuity and there is no intermittent electrical issue:
· Replace the EEC ( 4000KS ) Ref. AMM 73-22-34-000-010 Ref. AMM 73-22-34-400-010 .
Subtask 78-30-00-710-151-A
B. Test
(1) Do the operational test of the thrust reverser system with the CFDS (through FADEC 2A and 2B
menus), then without the CFDS and engine running Ref. AMM 78-31-00-710-041 .
5. Close-up
Subtask 78-30-00-860-091-A
A. Put the aircraft back to its initial configuration.
(1) Make sure that the thrust reverser halves 461AL and 462AR are closed Ref.
AMM 78-32-00-410-010 .
(2) Make sure that the fan cowls 447AL and 448AR are closed Ref. AMM 71-13-00-410-010 . [Rev.6 from Feb 2017] 2026.04.04 04:38:09 UTC