DOC AIRBUS | TSM A320FThrust-Reverser Blocker-Door Stow and Deploy Switches Feedback Disagree on Engine 1
TASK 78-31-00-810-835-A
Thrust-Reverser Blocker-Door Stow and Deploy Switches Feedback Disagree on Engine 1
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
3. Fault Confirmation
Subtask 78-31-00-710-118-A ** ON A/C NOT FOR ALL Subtask 78-31-00-710-118-B ** ON A/C NOT FOR ALL 4. Fault Isolation
Subtask 78-31-00-810-084-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:38:00 UTC
Thrust-Reverser Blocker-Door Stow and Deploy Switches Feedback Disagree on Engine 1
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 78-31-00-810-839-A | Thrust-Reverser Blocker-Door Stow-Switches Feedback Disagree on Engine 1 |
| TSM TASK 78-31-00-810-843-A | Thrust-Reverser Blocker-Door Deploy-Switches Feedback Disagree on Engine 1 |
| 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 78-31-17-000-040 | Removal of the Blocker Door Deploy Switch |
| AMM 78-31-17-400-001 | Installation of the Blocker Door Deploy Switch |
| AMM 78-31-17-400-040 | Installation of the Blocker Door Deploy Switch |
| AMM 78-32-41-000-001 | Removal of the Lower Blocker Door |
| AMM 78-32-41-000-002 | Removal of the Upper Blocker Door |
| AMM 78-32-41-000-040 | Removal of the Lower Blocker Door |
| AMM 78-32-41-000-041 | Removal of the Upper Blocker Door |
| AMM 78-32-41-400-001 | Installation of the Lower Blocker Door |
| AMM 78-32-41-400-002 | Installation of the Upper Blocker Door |
| AMM 78-32-41-400-040 | Installation of the Lower Blocker Door |
| AMM 78-32-41-400-041 | Installation of the Upper Blocker Door |
Subtask 78-31-00-710-118-A ** ON A/C NOT FOR ALL Subtask 78-31-00-710-118-B ** ON A/C NOT FOR ALL 4. Fault Isolation
Subtask 78-31-00-810-084-A ** ON A/C NOT FOR ALL
A. This fault message is generated if the ECU detects a disagreement between the blocker doors position indicated by the stow switches and the position indicated by the deploy switches through each ECU channel. The ECU cannot isolate the switches that are faulty. This message is triggered if dual failure condition is present.
(1) If the test gives the maintenance messages STOW SW, J5/J6, ECU and DEPL SW, J5/J6, ECU:
Subtask 78-31-00-810-084-B ** ON A/C NOT FOR ALL (1) If the test gives the maintenance messages STOW SW, J5/J6, ECU and DEPL SW, J5/J6, ECU:
- Do the related trouble shooting procedures (Ref. TSM TASK 78-31-00-810-839) and (Ref. TSM TASK 78-31-00-810-843).
NOTE: Do a check of the deploy-switch control levers for free operation. Seizure of the control lever shaft may trigger the wrong position indication of the blocker doors.
If damage is found:
If damage is found:
- Replace the hardware AMM 78-31-17-000-040 and AMM 78-31-17-400-040 or apply CMM 78-31-17 repair No.1.
NOTE: Do a check of the deploy-switch control levers and the bushings for gaps. A gap between the control lever shaft and the bushing can trigger the wrong position indication of the blocker door.
If damage is found:
If damage is found:
- Replace the hardware AMM 78-31-17-000-040 and AMM 78-31-17-400-040 or apply CMM 78-32-35 repair No. 29.
NOTE: Do a check of the blocker door pivot bolts and the bushings for gaps. A gap between the pivot bolt and the bushing can trigger the wrong position indication of the blocker door.
If damage is found:
If damage is found:
- Replace the hardware AMM 78-32-41-000-040 and AMM 78-32-41-400-040 or AMM 78-32-41-000-041 and AMM 78-32-41-400-041 or apply CMM 78-32-35 repair No. 29.
A. This fault message is generated if the ECU detects a disagreement between the blocker doors position indicated by the stow switches and the position indicated by the deploy switches through each ECU channel. The ECU cannot isolate the switches that are faulty. This message is triggered if dual failure condition is present.
(1) If the test gives the maintenance messages STOW SW, J5/J6, ECU and DEPL SW, J5/J6, ECU:
Subtask 78-31-00-710-186-A ** ON A/C NOT FOR ALL (1) If the test gives the maintenance messages STOW SW, J5/J6, ECU and DEPL SW, J5/J6, ECU:
- do the related trouble shooting procedures (Ref. TSM TASK 78-31-00-810-839) and (Ref. TSM TASK 78-31-00-810-843).
NOTE: Do a check of the deploy-switch control levers for free operation. Seizure of the control lever shaft may trigger the wrong position indication of the blocker doors.
If damage is found:
If damage is found:
- Replace hardware AMM 78-31-17-000-001 and AMM 78-31-17-400-001 or apply CMM 78-31-17 repair No.1.
NOTE: Do a check of the deploy-switch control levers and the bushings for gaps. A gap between the control lever shaft and the bushing can trigger the wrong position indication of the blocker door.
If damage is found:
If damage is found:
- Replace the hardware AMM 78-31-17-000-001 and AMM 78-31-17-400-001 or apply CMM 78-32-36 repair No. 46.
NOTE: Do a check of the blocker door pivot bolts and bushings for gap. Gap between the pivot bolt and bushing may trigger wrong position indication of the blocker door.
If damage is found:
If damage is found:
- replace hardware AMM 78-32-41-000-001 and AMM 78-32-41-400-001 or AMM 78-32-41-000-002 and AMM 78-32-41-400-002, or apply CMM 78-32-36 repair No. 46.
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.
(1) No additional maintenance action is required if the fault is not confirmed.
(2) Repeat the fault isolation procedure if the fault continues.