Cargo Door (Fwd) Handle Proximity Sensor Fault (28WV)

TASK 32-31-00-810-830-A
Cargo Door (Fwd) Handle Proximity Sensor Fault (28WV)

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 SW-HANDLE, FWD CARGO COMPT DOOR [28WV]
wiring
LGCIU-1 [5GA1]

2. Job Set-up Information
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

B. Referenced Information

REFERENCE	DESIGNATION
ASM 315400
AMM 32-31-71-000-001	Removal of the LGCIU
AMM 32-31-71-400-001	Installation of the LGCIU
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
AMM 52-71-12-000-001	Removal of the Proximity Switches
AMM 52-71-12-400-001	Installation of the Proximity Switches
TSM TASK 32-31-00-03	NORMAL EXTENSION AND RETRACTION - TASK SUPPORTING DATA

3. Fault Confirmation
Subtask 32-31-00-740-070-A

A. Test
(1) Do a BITE test on the LGCIU-1 AMM 32-69-00-740-001.
(a) Access LGCIU-1 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.

4. Fault Isolation
Subtask 32-31-00-810-081-A

A. Cargo Compartment Door Control

NOTE: The PROX SW-HANDLE, FWD CARGO COMPT DOOR [28WV] is installed on the FWD cargo door.

(1) Refer to AMM 52-71-12-000-001 Figure 401/TASK 52-71-12-991-001 and find the PROX SW-HANDLE, FWD CARGO COMPT DOOR [28WV] .
(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 32-31-00-03 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 315400. 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).

(4) On the proximity sensor, do a check of circuit isolation.
(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 SW-HANDLE, FWD CARGO COMPT DOOR [28WV] :
(a) Replace the PROX SW-HANDLE, FWD CARGO COMPT DOOR [28WV] AMM 52-71-12-000-001 and AMM 52-71-12-400-001.
(6) If the tests at Para. 4.A. (3) and (4) are satisfactory, then:
(a) Do a check of the wiring between the applicable proximity sensor electrical- connector and the LGCIU 1 ARINC tray ASM 315400.
(7) If there is circuit/interface fault, repair it.
(8) Do the L/G BITE test as in Para. 3.A. (1).
(9) If no fault is found at Para. 4.A. (5):
(a) Replace the LGCIU-1 [5GA1] AMM 32-31-71-000-001 and AMM 32-31-71-400-001.
(10) Do the GROUND SCANNING and make sure that the ground log is clear.

5. Close-up
Subtask 32-31-00-860-080-A

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:40:41 UTC