Differential Lock: Testing and Inspection

REMOVAL
REMOVE DIFFERENTIAL LOCK ACTUATOR

INSPECTION
1. INSPECT DIFFERENTIAL LOCK SYSTEM





a. Inspect the indicator light.
1. Check that the indicator light lights up for approximately 1 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.
Differential lock is applied to the rear wheel at this time.

HINT: 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.
Differential lock is released for the rear wheel at this time.
5. Check the voltage between the terminals of the 4WD control ECU when switching the Differential lock control switch with the speedometer, registering approximately 8 km/h (5 mph) or more.
6. Check that the indicator lights blink when 2WD mode is set.
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 DIFFERENTIAL LOCK SYSTEM CIRCUIT
a. Inspect the battery positive voltage.
Battery positive voltage: 10 - 14 V








b. Inspect the system circuit with the connector disconnected.
Disconnect the connector from the 4WD control ECU and inspect the connector on the wire harness side, as shown in the chart.

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

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.
If the circuit is not as specified, replace the ECU.
5. Install the ECU in place.
3. INSPECT DIFFERENTIAL LOCK COMPONENTS
a. Inspect the relay operation.
1. Jack up the vehicle.





2. Use a heater main relay and connect it, as shown in the chart.

NOTICE: Connect the terminals being careful not to touch the neigh boring 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 1 and terminal 4.

HINT: Continuity doesn't exist, replace the switch.





c. Inspect the Differential lock indicator switch.
1. Check that there is continuity exists between terminals when the switch is pushed (differential locked position).
2. Check continuity doesn't exist when the switch is free (differential unlocked position).

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

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

INSTALLATION
INSTALL DIFFERENTIAL LOCK ACTUATOR