DOC AIRBUS | TSM A320FR MLG Compressed/Extended Proximity Sensor Failed to Flight Condition
TASK 32-31-00-810-813-A
R MLG Compressed/Extended Proximity Sensor Failed to Flight Condition
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 32-31-00-740-053-A
Subtask 32-31-00-810-064-A
Subtask 32-31-00-860-056-A
[Rev.8 from Aug 2018]
2026.04.04 04:31:19 UTC
R MLG Compressed/Extended Proximity Sensor Failed to Flight Condition
WARNING:
MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. MOVEMENT OF THE LANDING GEAR CAN CAUSE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.
1. Possible Causes- PROX SNSR-R L/G EXT, SYS 1 [20GA]
- PROX SNSR-R L/G EXT, SYS 2 [22GA]
- wiring
- LGCIU-1 [5GA1]
- LGCIU-2 [5GA2]
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | MULTIMETER - STANDARD |
| No specific | AR | TESTER - INSULATION RESISTANCE |
| 38-368-02 | 1 | UNIT-TEST,SENSOR |
| 38-368-03 | 1 | UNIT-TEST,SENSOR |
| REFERENCE | DESIGNATION |
|---|---|
| AMM 24-41-00-861-002 | Energize the Aircraft Electrical Circuits from the External Power |
| AMM 32-31-00-040-003 | Check of the System 2 Proximity Sensors of the Landing Gear and the Landing Gear Doors |
| ASM 323103 | |
| ASM 323104 | |
| AMM 32-31-71-000-001 | Removal of the LGCIU |
| AMM 32-31-71-400-001 | Installation of the LGCIU |
| AMM 32-31-73-000-001 | Removal of the MLG Proximity-Sensors |
| AMM 32-31-73-400-001 | Installation of the MLG Proximity-Sensors |
| AMM 32-69-00-740-001 | BITE Check of Landing-Gear Control Interface-Unit (LGCIU) With Use of MCDU to Ensure that Continuous BITE is Operative |
| TSM TASK 32-31-00-03 | NORMAL EXTENSION AND RETRACTION - TASK SUPPORTING DATA |
Subtask 32-31-00-740-053-A
A. Test
(1) Make sure that the aircraft electrical circuits are energized with an external power supply AMM 24-41-00-861-002. If external power is not available, go to Para. 4. A. (1).
(2) Do a BITE test on the LGCIU-1 (2) AMM 32-69-00-740-001.
(3) Get an access to the LGCIU-1 (2) TROUBLE SHOOTING (ground) and read the BITE test fault number(s) for fault confirmation (Ref. TSM 32-31-00 PB 301).
4. Fault Isolation(1) Make sure that the aircraft electrical circuits are energized with an external power supply AMM 24-41-00-861-002. If external power is not available, go to Para. 4. A. (1).
(2) Do a BITE test on the LGCIU-1 (2) AMM 32-69-00-740-001.
(3) Get an access to the LGCIU-1 (2) TROUBLE SHOOTING (ground) and read the BITE test fault number(s) for fault confirmation (Ref. TSM 32-31-00 PB 301).
NOTE: The tables in the (Ref. TSM 32-31-00 PB 301) show the CFDS FAULT message.
(4) Do the fault isolation. Subtask 32-31-00-810-064-A
A. Procedure
(1) Refer to AMM 32-31-73-000-001 Figure 404/TASK 32-31-73-991-004, and find the PROX SNSR-R L/G EXT, SYS 1 [20GA] and the PROX SNSR-R L/G EXT, SYS 2 [22GA] .
(2) If the BITE test shows a proximity sensor fault, do the steps that follow:
(a) At the applicable proximity sensor, release the electrical-connector.
(b) If the 38-368-02 UNIT-TEST,SENSOR or the 38-368-03 UNIT-TEST,SENSOR is available, do the troubleshooting procedure of the proximity sensor32-31-00-03 TSM TASK 32-31-00-03 .
(3) Use the MULTIMETER - STANDARD and do a check of the resistance between pins A and B of the proximity sensor, ASM 323103 or ASM 323104. Make sure that the resistance is:
(a) Connect pins A and B together.
(b) Connect one test lead of the TESTER - INSULATION RESISTANCE to pins AB and the other test lead to the case.
(c) Supply a test signal for five seconds and read the resistance value shown.
(d) Make sure that the resistance is more than 400 Megohms.
(5) If one of the two tests at Para. 4.A. (3) and (4) is unsatisfactory for the PROX SNSR-R L/G EXT, SYS 1 [20GA] or the PROX SNSR-R L/G EXT, SYS 2 [22GA] :
(a) Replace the unserviceable proximity sensor AMM 32-31-73-000-001 and AMM 32-31-73-400-001.
(6) If the tests at Para. 4.A. (3) and (4) are satisfactory, then:
(a) Do a check of the wiring between the applicable electrical-connector and LGCIU 1 or LGCIU 2 ARINC tray, ASM 323103 or ASM 323104.
(7) If there is a circuit/interface fault, repair it.
(8) Do the L/G BITE test as in Para. 3.A.
(9) If no fault is found at Para. 4.A. (6):
(a) Replace the LGCIU-1 [5GA1] or the LGCIU-2 [5GA2] AMM 32-31-71-000-001 AMM 32-31-71-400-001.
(10) Do the GROUND SCANNING and make sure that the ground log is clear.
(11) If MMEL conditions apply to the PROX SNSR-R L/G EXT, SYS 2 [22GA] :
(a) Do the deactivation procedure of the proximity sensor AMM 32-31-00-040-003.
5. Close-up(1) Refer to AMM 32-31-73-000-001 Figure 404/TASK 32-31-73-991-004, and find the PROX SNSR-R L/G EXT, SYS 1 [20GA] and the PROX SNSR-R L/G EXT, SYS 2 [22GA] .
(2) If the BITE test shows a proximity sensor fault, do the steps that follow:
(a) At the applicable proximity sensor, release the electrical-connector.
(b) If the 38-368-02 UNIT-TEST,SENSOR or the 38-368-03 UNIT-TEST,SENSOR is available, do the troubleshooting procedure of the proximity sensor
(3) Use the MULTIMETER - STANDARD and do a check of the resistance between pins A and B of the proximity sensor, ASM 323103 or ASM 323104. Make sure that the resistance is:
- Between 11 and 13 ohms for a ferrite proximity sensor (PN 8-484-01)
- Between 15 and 17 ohms for an all metal proximity sensor (PN 8-933-01).
(a) Connect pins A and B together.
(b) Connect one test lead of the TESTER - INSULATION RESISTANCE to pins AB and the other test lead to the case.
(c) Supply a test signal for five seconds and read the resistance value shown.
(d) Make sure that the resistance is more than 400 Megohms.
(5) If one of the two tests at Para. 4.A. (3) and (4) is unsatisfactory for the PROX SNSR-R L/G EXT, SYS 1 [20GA] or the PROX SNSR-R L/G EXT, SYS 2 [22GA] :
(a) Replace the unserviceable proximity sensor AMM 32-31-73-000-001 and AMM 32-31-73-400-001.
(6) If the tests at Para. 4.A. (3) and (4) are satisfactory, then:
(a) Do a check of the wiring between the applicable electrical-connector and LGCIU 1 or LGCIU 2 ARINC tray, ASM 323103 or ASM 323104.
(7) If there is a circuit/interface fault, repair it.
(8) Do the L/G BITE test as in Para. 3.A.
(9) If no fault is found at Para. 4.A. (6):
(a) Replace the LGCIU-1 [5GA1] or the LGCIU-2 [5GA2] AMM 32-31-71-000-001 AMM 32-31-71-400-001.
(10) Do the GROUND SCANNING and make sure that the ground log is clear.
(11) If MMEL conditions apply to the PROX SNSR-R L/G EXT, SYS 2 [22GA] :
(a) Do the deactivation procedure of the proximity sensor AMM 32-31-00-040-003.
Subtask 32-31-00-860-056-A
A. Put the aircraft back to its initial configuration.