DOC AIRBUS | TSM A320FFWD Cargo - Door Indication Proximity-Switch TGT POS Fault (5MJ, 28WV, 30WV)
TASK 32-31-00-810-877-A
FWD Cargo - Door Indication Proximity-Switch TGT POS Fault (5MJ, 28WV, 30WV)
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 32-31-00-700-054-A
Subtask 32-31-00-810-135-A
[Rev.8 from Aug 2018]
2026.04.04 04:31:25 UTC
FWD Cargo - Door Indication Proximity-Switch TGT POS Fault (5MJ, 28WV, 30WV)
WARNING:
PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:
1. Possible Causes- THE FLIGHT CONTROLS
- THE FLIGHT CONTROL SURFACES
- THE LANDING GEAR AND THE RELATED DOORS
- COMPONENTS THAT MOVE.
- PROX SW-HANDLE, FWD CARGO COMPT DOOR [28WV]
- PROX SW-FRAME, FWD CARGO COMPT DOOR [30WV]
- SW-LOCKING SHAFT [5MJ]
- LGCIU-1 [5GA1]
- LGCIU-2 [5GA2]
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | INDUCTANCE METER 1KHZ |
| No specific | AR | MULTIMETER - STANDARD |
| No specific | AR | TESTER - INSULATION RESISTANCE |
| REFERENCE | DESIGNATION |
|---|---|
| AMM 32-31-71-000-001 | Removal of the LGCIU |
| AMM 32-31-71-400-001 | Installation of the LGCIU |
| AMM 32-31-73-820-008 | Inductance Check of the Proximity Sensors/Switches |
| AMM 52-31-00-710-001 | Operational Test of the FWD Cargo-Compartment Door |
| AMM 52-31-00-720-001 | Functional Check of Forward Cargo Compartment Door, Comprising Functional Checks of Locking Mechanism, Interlock Mechanism, Drift Pin Mechanism, ..... |
| AMM 52-31-11-820-001 | Adjustment of the FWD Cargo-Compartment Door |
| AMM 52-35-13-000-002 | Removal of the Proximity Switches |
| AMM 52-35-13-400-002 | Installation of the Proximity Switches |
| AMM 52-71-00-820-003 | Adjustment of the Proximity Switches of the Cargo Compartment Door Threshold |
| AMM 52-71-00-820-004 | Adjustment of the Proximity Switches of the Locking Handle of the Cargo Compartment Doors |
| AMM 52-71-12-000-001 | Removal of the Proximity Switches |
| AMM 52-71-12-000-002 | Removal of the Proximity Switches |
| AMM 52-71-12-400-001 | Installation of the Proximity Switches |
| AMM 52-71-12-400-002 | Installation of the Proximity Switches |
Subtask 32-31-00-700-054-A
A. Test
(1) Do an operational test of the FWD cargo-compartment door AMM 52-31-00-710-001:
(a) If the test is OK and the DOOR/OXY page shows amber, do the fault isolation procedure in Para. 4.A.
(b) If the test is OK and the DOOR/OXY page shows green, no more maintenance steps are necessary.
4. Fault Isolation(1) Do an operational test of the FWD cargo-compartment door AMM 52-31-00-710-001:
(a) If the test is OK and the DOOR/OXY page shows amber, do the fault isolation procedure in Para. 4.A.
(b) If the test is OK and the DOOR/OXY page shows green, no more maintenance steps are necessary.
NOTE: The LGCIU only monitors the target position (TGT POS) of the proximity-switches, when all the shock absorbers are extended. The BITE test cannot identify a TGT POS fault condition. Ground Scanning can show TGT POS messages, if all the shock absorbers are extended.
Subtask 32-31-00-810-135-A
A. Fault Isolation
(1) For the applicable proximity-switch shown on the PFR:
(a) Make sure that all the electrical connections are clean and in the correct condition.
(b) Make sure that the proximity-switch, the target and the target lever are clean.
(c) Make sure that there is no damage to the proximity-switch bracket and the target lever. If you find damage:
1 Do the applicable repair procedure.
2 Do an adjustment of the clearance between the proximity-switch and its target:
(2) Use an INDUCTANCE METER 1KHZ and do an inductance check of the applicable proximity-switch AMM 32-31-73-820-008:
(a) Measure the resistance between pins A and B, which must be:
2 If the resistance value is correct, do step (4).
(4) Use a TESTER - INSULATION RESISTANCE and do a check of the circuit-isolation of the applicable proximity-switch, shown on the PFR:
(a) Connect the pins A and B together.
(b) Measure the resistance between pins AB and the case of the proximity-switch, which must be more than 400 Megohms:
(6) Replace the applicable LGCIU:
(7) If the fault occurs again immediately after a pressurized flight, do as follows:
(a) Visually examine the door mechanism and make sure that:
(c) Do an operational test of the FWD cargo-compartment door AMM 52-31-00-710-001.
(d) Do a functional test of the FWD cargo-compartment door AMM 52-31-00-720-001.
(e) Do an adjustment of the FWD cargo-compartment door AMM 52-31-11-820-001.
(f) Do an adjustment of the proximity-switch and its target:
(1) For the applicable proximity-switch shown on the PFR:
(a) Make sure that all the electrical connections are clean and in the correct condition.
(b) Make sure that the proximity-switch, the target and the target lever are clean.
(c) Make sure that there is no damage to the proximity-switch bracket and the target lever. If you find damage:
1 Do the applicable repair procedure.
2 Do an adjustment of the clearance between the proximity-switch and its target:
- For proximity-switch PROX SW-HANDLE, FWD CARGO COMPT DOOR [28WV] AMM 52-71-00-820-004
- For proximity-switch PROX SW-FRAME, FWD CARGO COMPT DOOR [30WV] AMM 52-71-00-820-003
- For proximity-switch SW-LOCKING SHAFT [5MJ] AMM 52-35-13-400-002.
(2) Use an INDUCTANCE METER 1KHZ and do an inductance check of the applicable proximity-switch AMM 32-31-73-820-008:
- If the inductance value is not correct, do step (5)
- If the inductance value is correct, do step (3).
NOTE: It is recommended that you do a check of the inductance of the other two proximity-switches (related to the FWD cargo door). Replace those proximity-switches that are not specified.
(3) Use a MULTIMETER - STANDARD and do a check of the resistance of the applicable proximity-switch shown on the PFR: (a) Measure the resistance between pins A and B, which must be:
- 12 ohms for proximity-switches, P/N ABS0121-10 and P/N ABS0121-31
- 19 ohms for proximity-switch, P/N ABS0121-40.
2 If the resistance value is correct, do step (4).
(4) Use a TESTER - INSULATION RESISTANCE and do a check of the circuit-isolation of the applicable proximity-switch, shown on the PFR:
(a) Connect the pins A and B together.
(b) Measure the resistance between pins AB and the case of the proximity-switch, which must be more than 400 Megohms:
- If the resistance value is not correct, do step (5)
- If the resistance value is correct, do step (6).
NOTE: The test signal is supplied for five seconds before the resistance value is read.
(5) Replace the applicable proximity-switch: - For proximity-switch PROX SW-HANDLE, FWD CARGO COMPT DOOR [28WV] AMM 52-71-12-000-001 and AMM 52-71-12-400-001
- For proximity-switch PROX SW-FRAME, FWD CARGO COMPT DOOR [30WV] AMM 52-71-12-000-002 and AMM 52-71-12-400-002
- For proximity-switch SW-LOCKING SHAFT [5MJ] AMM 52-35-13-000-002 and AMM 52-35-13-400-002.
(6) Replace the applicable LGCIU:
- If the PFR shows a message related to proximity-switches 28WV or 30WV, replace the LGCIU-1 [5GA1] AMM 32-31-71-000-001 and AMM 32-31-71-400-001
- If the PFR shows a message related to proximity-switch 5MJ, replace the LGCIU-2 [5GA2] AMM 32-31-71-000-001 and AMM 32-31-71-400-001.
(7) If the fault occurs again immediately after a pressurized flight, do as follows:
(a) Visually examine the door mechanism and make sure that:
- There is no damage or loose attachments
- The vent flap is fully closed and the door handle is in the recess of the door structure.
(c) Do an operational test of the FWD cargo-compartment door AMM 52-31-00-710-001.
(d) Do a functional test of the FWD cargo-compartment door AMM 52-31-00-720-001.
(e) Do an adjustment of the FWD cargo-compartment door AMM 52-31-11-820-001.
(f) Do an adjustment of the proximity-switch and its target:
- For proximity-switch PROX SW-HANDLE, FWD CARGO COMPT DOOR [28WV] AMM 52-71-00-820-004
- For proximity-switch PROX SW-FRAME, FWD CARGO COMPT DOOR [30WV] AMM 52-71-00-820-003
- For proximity-switch SW-LOCKING SHAFT [5MJ] AMM 52-35-13-400-002.
NOTE: To identify a TGT POS fault, the LGCIU must be correctly connected to the related proximity-switch. Thus a check of the aircraft wiring is not necessary.