DOC AIRBUS | TSM A320FNLG Uplock Proximity Sensor Fault
TASK 32-31-00-810-827-A
NLG Uplock Proximity Sensor Fault
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 32-31-00-740-067-A
Subtask 32-31-00-810-078-A
Subtask 32-31-00-860-077-A
[Rev.8 from Aug 2018]
2026.04.04 04:31:20 UTC
NLG Uplock Proximity Sensor Fault
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.
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 SNSR-NLG UPLK, SYS 1 [12GA]
- PROX SNSR-NLG UPLK, SYS 2 [13GA]
- 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 32-22-00-010-001 | Nose Gear Doors - Ground Doors Opening |
| 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 32-31-73-000-005 | Removal of the NLG Proximity-Sensors |
| AMM 32-31-73-400-005 | Installation of the NLG 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 32-31-00-740-067-A
A. Test
(1) Do a BITE test on the LGCIU-1 (2) AMM 32-69-00-740-001:
(a) Access LGCIU-1 (2) TROUBLE SHOOTING (ground) and read the BITE test fault number(s) for fault confirmation (refer to TSM 323100 PB 301).
4. Fault Isolation(1) Do a BITE test on the LGCIU-1 (2) AMM 32-69-00-740-001:
(a) Access LGCIU-1 (2) TROUBLE SHOOTING (ground) and read the BITE test fault number(s) for fault confirmation (refer to TSM 323100 PB 301).
NOTE: The table shows the CFDS FAULT message.
(2) Do the fault isolation. Subtask 32-31-00-810-078-A
A. Procedure
(1) Open the N L/G doors to get access to the proximity sensor(s) AMM 32-22-00-010-001.
(2) Refer to AMM 32-31-73-000-005 Figure 406/TASK 32-31-73-991-007, and find the PROX SNSR-NLG UPLK, SYS 1 [12GA] and the PROX SNSR-NLG UPLK, SYS 2 [13GA] .
(3) 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 .
(4) Use the MULTIMETER - STANDARD and do a check of the resistance between pins A and B of the proximity sensor, ASM 323103 and 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.
(6) If one of the two tests at Para. 4.A. (4) and (5) is unsatisfactory for the PROX SNSR-NLG UPLK, SYS 1 [12GA] or the PROX SNSR-NLG UPLK, SYS 2 [13GA] :
(a) Replace the unserviceable proximity sensor AMM 32-31-73-000-005 and AMM 32-31-73-400-005.
(7) If the tests at Para. 4.A. (4) and (5) are satisfactory, then:
(a) Do a check of the wiring between the applicable proximity sensor electrical-connector and LGCIU 1 or LGCIU 2 ARINC tray, ASM 323103 or ASM 323104.
(8) If there is a circuit/interface fault, repair it.
(9) Do the L/G BITE test as in Para. 3.A. (1).
(10) If no fault is found at Para. 4.A. (7):
(a) Replace the LGCIU-1 [5GA1] or the LGCIU-2 [5GA2] AMM 32-31-71-000-001 AMM 32-31-71-400-001.
(11) Do the GROUND SCANNING and make sure that the ground log is clear.
(12) If MMEL conditions apply to the PROX SNSR-NLG UPLK, SYS 2 [13GA] :
(a) Do the deactivation procedure of the proximity sensor AMM 32-31-00-040-003.
5. Close-up(1) Open the N L/G doors to get access to the proximity sensor(s) AMM 32-22-00-010-001.
(2) Refer to AMM 32-31-73-000-005 Figure 406/TASK 32-31-73-991-007, and find the PROX SNSR-NLG UPLK, SYS 1 [12GA] and the PROX SNSR-NLG UPLK, SYS 2 [13GA] .
(3) 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
(4) Use the MULTIMETER - STANDARD and do a check of the resistance between pins A and B of the proximity sensor, ASM 323103 and 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.
(6) If one of the two tests at Para. 4.A. (4) and (5) is unsatisfactory for the PROX SNSR-NLG UPLK, SYS 1 [12GA] or the PROX SNSR-NLG UPLK, SYS 2 [13GA] :
(a) Replace the unserviceable proximity sensor AMM 32-31-73-000-005 and AMM 32-31-73-400-005.
(7) If the tests at Para. 4.A. (4) and (5) are satisfactory, then:
(a) Do a check of the wiring between the applicable proximity sensor electrical-connector and LGCIU 1 or LGCIU 2 ARINC tray, ASM 323103 or ASM 323104.
(8) If there is a circuit/interface fault, repair it.
(9) Do the L/G BITE test as in Para. 3.A. (1).
(10) If no fault is found at Para. 4.A. (7):
(a) Replace the LGCIU-1 [5GA1] or the LGCIU-2 [5GA2] AMM 32-31-71-000-001 AMM 32-31-71-400-001.
(11) Do the GROUND SCANNING and make sure that the ground log is clear.
(12) If MMEL conditions apply to the PROX SNSR-NLG UPLK, SYS 2 [13GA] :
(a) Do the deactivation procedure of the proximity sensor AMM 32-31-00-040-003.
Subtask 32-31-00-860-077-A
A. Put the aircraft back to its initial configuration.