W DOC AIRBUS | TSM A320F

Thrust-Reverser Blocker-Door Deploy-Switches Feedback Disagree on Engine 2

TASK 78-31-00-810-844-A
Thrust-Reverser Blocker-Door Deploy-Switches Feedback Disagree on Engine 2

1. Possible Causes
  • SW-BLOCKER DOOR DEPLOY, L [4103KS1]
  • SW-BLOCKER DOOR DEPLOY, R [4103KS2]
  • ECU [4000KS]
  • thrust reverser harness
  • harness J5
  • harness J6
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AWM 715105
AMM 71-51-43-000-004
Removal of the ECU (Channel B) to Thrust Reverser Junction Box Harnesses
AMM 71-51-43-000-044
Removal of the Thrust Reverser (Channel A and B) Harness
AMM 71-51-43-000-049
Removal of the ECU (Channel A) to Thrust Reverser Junction Box Harnesses
AMM 71-51-43-400-004
Installation of the ECU (Channel B) to thrust Reverser Junction Box Harnesses
AMM 71-51-43-400-044
Installation of the Thrust Reverser (Channel A and B) Harness
AMM 71-51-43-400-049
Installation of the ECU (Channel A) to Thrust Reverser Junction Box Harnesses
AMM 71-51-44-000-002
Removal of the Thrust Reverser Harness 238W0908
AMM 71-51-44-400-002
Installation of the Thrust Reverser Harness 238W0908
AMM 73-21-60-000-001
Removal of the Electronic Control Unit (ECU)
AMM 73-21-60-400-001
Installation of the Electronic Control Unit (ECU)
ASM 732516
AMM 78-31-00-710-040
Operational Test of the Thrust Reverser System
AMM 78-31-00-710-042
Operational Test of the Thrust Reverser System
AMM 78-31-17-000-001
Removal of the Blocker Door Deploy Switch
AMM 78-31-17-210-001
Detailed Visual Inspection of the Deploy Switches and Triggers
AMM 78-31-17-210-040
Detailed Visual Inspection of the Deploy Switches and Triggers
AMM 78-31-17-400-001
Installation of the Blocker Door Deploy Switch
AMM 78-31-42-210-040
Detailed Visual Inspection of the Electrical Harness
AMM 78-31-42-210-041
Detailed Visual Inspection of the electrical Harness
AMM 78-32-41-860-001
Manual Deployment of the Blocker Door
AMM 78-32-41-860-040
Manual Deployment of the Blocker Door
3. Fault Confirmation
Subtask 78-31-00-710-134-A ** ON A/C NOT FOR ALL
A. Do the operational test of the thrust reverser system (2A and 2B) AMM 78-31-00-710-040.
Subtask 78-31-00-710-134-B ** ON A/C NOT FOR ALL
A. Do the operational test of the thrust reverser system (2A and 2B) AMM 78-31-00-710-042.
4. Fault Isolation
Subtask 78-31-00-810-093-A ** ON A/C NOT FOR ALL
A. This fault message is generated if there is a disagreement between channel A and channel B on the thrust-reverser blocker-door deploy switches signal. Most probable cause is deploy switches or a harness failure.
   (1) If the test gives the maintenance message DEPL SW, J5/J6, ECU on the channel A or B:
  • make sure that the thrust-reverser blocker doors are in the stowed position,
  • disconnect the harnesses J5 and J6 from the ECU (4000KS),
  • do a resistance check of the harnesses J5 and J6 AWM 715105 between:
    . pins 21 and 22 (>10 megohms)
    . pins 21 and 11 (>10 megohms)
    . pin 21 and the ground (>10 megohms).
     (a) If the resistance values are out of the specified limits:
  • with the thrust-reverser blocker doors in the stowed position, disconnect the harnesses J5 and J6 from each deploy switch,
  • do a resistance check on each deploy switch AWM 715105 between:
    . pins 3 and 2 (>10 megohms)
    . pins 4 and 5 (>10 megohms)
    . pins 4 and 1 (>10 megohms)
    . pin 4 and the ground (>10 megohms).
       1 If the resistance values are out of the specified limits:
       2 If the resistance values are in the specified limits:
  • do a continuity and insulation check of the thrust reverser and harnesses J5 and J6 between the deploy switches including the junction box (4100KS) ASM 732516,
  • do a visual check of each connector for correct condition.
         a If damage is found:
  • repair or replace as required.
         b If nothing is found:
     (b) If the resistance values are in the specified limits:
  • do a manual deployment of the thrust reverser blocker doors AMM 78-32-41-860-040
  • do a resistance check of the harnesses J5 and J6 AWM 715105 between:
    . pins 21 and 22 (<5 ohms)
    . pins 21 and 11 (>10 megohms)
    . pin 21 and the ground (>10 megohms).
       1 If the resistance values are out of the specified limits:
  • with the thrust-reverser blocker doors in the deployed position, disconnect the harnesses J5 and J6 from each deploy switch,
  • do a resistance check on each deploy switch AWM 715105 between:
    . pins 3 and 2 (<5 ohms)
    . pins 4 and 5 (<5 ohms)
    . pins 4 and 1 (>10 megohms)
    . pin 4 and the ground (>10 megohms).
         a If the resistance values are out of the specified limits:
         b If the resistance values are in the specified limits:
  • do a continuity and insulation check of the thrust reverser and harnesses J5 and J6 between the deploy switches including the junction box (4100KS) ASM 732516,
  • do a visual check of each connector for correct condition.
         c If damage is found:
  • repair or replace as required.
         d If nothing is found:
       2 If the resistance values are in the specified limits:
  • do a continuity and insulation check of the thrust reverser and harnesses J5 and J6 between the stow switches including the junction box (4100KS) ASM 732516,
  • do a visual check of each connector for correct condition.
         a If damage is found:
  • repair or replace as required.
         b If nothing is found:
   (2) If the test does not give the maintenance message DEPL SW, J5/J6, ECU:
  • do a check of the connectors of the thrust reverser harness and harnesses J5 and J6 for looseness, contamination, and bent pins.
     (a) If damage is found:
     (b) If nothing is found:
  • do a check of the harness routing and look for chafing or cut in the harness envelope.
       1 If damage is found:
       2 If nothing is found and the fault continues while the fault message is never confirmed during the thrust reverser test:
         a If the fault continues:
         b If the fault continues:
Subtask 78-31-00-810-093-B ** ON A/C NOT FOR ALL
A. This fault message is generated if there is a disagreement between channel A and channel B on the thrust-reverser blocker-door deploy switches signal. Most probable cause is deploy switches or a harness failure.
   (1) If the test gives the maintenance message DEPL SW, J5/J6, ECU on the channel A or B:
  • make sure that the thrust reverser blocker doors are in the stowed position,
  • disconnect the harnesses J5 and J6 from the ECU (4000KS),
  • do a resistance check of the harnesses J5 and J6 AWM 715105 between:
    . pins 21 and 22 (>10 megohms)
    . pins 21 and 11 (>10 megohms)
    . pin 21 and the ground (>10 megohms).
     (a) If the resistance values are out of the specified limits:
  • with the thrust-reverser blocker doors in the stowed position, disconnect the harnesses J5 and J6 from each deploy switch,
  • do a resistance check on each deploy switch AWM 715105 between:
    . pins 3 and 2 (>10 megohms)
    . pins 4 and 5 (>10 megohms)
    . pins 4 and 1 (>10 megohms)
    . pin 4 and the ground (>10 megohms).
       1 If the resistance values are out of the specified limits:
       2 If the resistance values are in the specified limits:
  • do a continuity and insulation check of the thrust reverser and harnesses J5 and J6 between the deploy switches including the junction box (4100KS) ASM 732516,
  • do a visual check of each connector for correct condition.
         a If damage is found:
  • repair or replace as required.
         b If nothing is found:
     (b) If the resistance values are in the specified limits:
  • do a manual deployment of the thrust-reverser blocker doors AMM 78-32-41-860-001
  • do a resistance check of the harnesses J5 and J6 AWM 715105 between:
    . pins 21 and 22 (<5 ohms)
    . pins 21 and 11 (>10 megohms)
    . pin 21 and the ground (>10 megohms).
       1 If the resistance values are out of the specified limits:
  • with the thrust-reverser blocker doors in the deployed position, disconnect the harnesses J5 and J6 from each deploy switch,
  • do a resistance check on each deploy switch AWM 715105 between:
    . pins 3 and 2 (<5 ohms)
    . pins 4 and 5 (<5 ohms)
    . pins 4 and 1 (>10 megohms)
    . pin 4 and the ground (>10 megohms).
         a If the resistance values are out of the specified limits:
         b If the resistance values are in the specified limits:
  • do a continuity and insulation check of the thrust reverser and harnesses J5 and J6 between the deploy switches including the junction box (4100KS) ASM 732516,
  • do a visual check of each connector for correct condition.
         c If damage is found:
  • repair or replace as required.
         d If nothing is found:
       2 If the resistance values are in the specified limits:
  • do a continuity and insulation check of the thrust reverser and harnesses J5 and J6 between the stow switches including the junction box (4100KS) ASM 732516,
  • do a visual check of each connector for correct condition.
         a If damage is found:
  • repair or replace as required.
         b If nothing is found:
   (2) If the test does not give the maintenance message DEPL SW, J5/J6, ECU:
  • do a check of the connectors of the thrust reverser harness and harnesses J5 and J6 for looseness, contamination, and bent pins.
     (a) If damage is found:
     (b) If nothing is found:
  • do a check of the harness routing and look for chafing or cut in the harness envelope.
       1 If damage is found:
       2 If nothing is found and the fault continues while the fault message is never confirmed during the thrust reverser test:
         a If the fault continues:
         b If the fault continues:
Subtask 78-31-00-710-135-A ** ON A/C NOT FOR ALL
B. Do the test given in Para. 3.A.
   (1) No additional maintenance action is required if the fault is not confirmed.
   (2) Repeat the fault isolation procedure if the fault continues.
[Rev.8 from Aug 2018] 2026.04.04 04:41:30 UTC
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