Inspection

Differential Locking System:

INSPECTION
1. Inspect the differential lock system by performing these procedures.





a. Inspect the indicator light, check that the indicator light lights up for approx. one second when the ignition switch is turned on.
b. Inspect the differential lock operation.
1. Jack up the vehicle then start the engine.
2. Shift the transfer shift lever to the L4 position.
3. When the differential lock control switch is set to the ON position the indicator light is turned on. The differential lock is applied to the rear wheel at this time.

NOTE: If the gears of the differential lock system are not meshed, the indicator light remains blinking, so rotate the tires to mesh the gear.

4. When the differential lock control switch is at the off position, the indicator light goes off, the differential lock is released for the rear wheel at this time.





5. Check the voltage between the terminals of the four wheel drive control ECU when switching the differential lock control switch with the speedometer, registering approx. 8 km/hr. (5 mph) or more. With the switch position on, the specified value at terminal M1-M2 is 0.5 V or less (No change).
6. Check that the indicator lights blink when the two wheel drive mode is set. The differential lock is released for both the rear wheels at this time.
7. Return the differential lock control switch to OFF.
8. Stop the engine and lower the vehicle.

2. Inspect the differential lock system circuit, doing the following.
a. Inspect the battery positive voltage, it should be 10-14 V.








b. Inspect the system circuit with the connector disconnected. Disconnect the connector from the four wheel drive control ECU and inspect the connector on the wire harness side, as shown in the chart.

NOTE: If the circuit is not as specified, check and repair or replace the trouble part shown in the table above.

c. Inspect the system circuit with the connector connected.
1. Turn the ignition switch to the ON position.
2. Keep the center differential lock condition.
3. Remove the differential lock ECU.
4. Using a voltmeter, measure the voltage when the differential lock control switch is in the position, as shown below, if the circuit is not as specified, replace the ECU.








5. Install the ECU in place.

3. Inspect the differential lock components by doing the following.
a. Inspect the relay operation.
1. Jack up the vehicle.





2. Use a heater main relay and connect it, as shown below.

NOTE: Connect the terminals being careful not to touch the neighboring terminals or metallic parts of the relay housing.





3. Rotate the tire and check that differential lock has occurred. If operation is not as specified, replace the actuator.





b. Inspect the differential lock control switch continuity. Inspect the switch continuity between terminal one to terminal four.

NOTE: If it is not continuity, replace the switch.





c. Inspect the differential lock indicator switch.
1. Check that there is continuity between terminals when the switch is pushed (differential connected position).
2. Check that there is no continuity when the switch is free (differential disconnected position).

NOTE: If operation is not as specified, replace the switch.

d. Inspect the transfer L4 switch.
e. Inspect the vehicle speed sensor.

4. Install the differential lock actuator.

NOTE: For installation & removal refer to Service and Repair