DIFFERENTIAL SYSTEM (w/ Differential Lock) INSPECTION


  1. INSPECT DIFFERENTIAL LOCK SYSTEM

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    1. Inspect the indicator light.


      1. Check that the indicator light lights up for appox. 1 second when the ignition switch is turned ON.

    2. Inspect the differential lock operation.


      1. Jack up the vehicle then start the engine.

      2. Shift the transfer shift lever to L position.

      3. When the differential lock control switch is set to the ON position, the indicator light is pushed on. Differential lock is applied to the rear wheel at this time.

        Tech Tips

        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. A01J74CE01

        Check the voltage between the terminals of the four wheel drive control ECU when switching the differential control switch with the speedomemter, registering approx. 8 km/h (5 mph) or more.

        Switch position Terminal Specified value
        ON M1 to M2 0.5 V or less (No change)

      6. Return the differential lock control switch to OFF.

      7. Stop the engine and lower the vehicle.

  2. CHECK WIRE HARNESS AND CONNECTOR

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    1. Inspect the system circuit with the connector disconnected.


      1. Disconnect the connector from the four wheel drive control ECU and inspect the connector on the wire harness side, as shown in the table.

        Standard voltage:
        Tester Connection Trouble Part Condition Specified value
        M1 - M2 Rear differential lock actuator - Less than 100 Ω
        GND - Body ground Body ground - Continuity
        SPD - Body ground Speed sensor Vehicle moves slowly 1 pulse 40 cm (15.75 in.)
        IG - Body ground Differential fuse Ignition switch ON 10 to 14 V
        RLP - Body ground Rear differential lock indicator switch Ignition switch ON with indicator light ON About 0 V
        Ignition switch ON with indicator light OFF 10 to 14 V
        4WD - Body ground L position switch Ignition switch ON with transfer shift lever except L About 0 V
        Ignition switch ON with transfer shift lever L 10 to 14 V
        R - Body ground Differential lock control switch Ignition switch ON with differential lock control switch ON 10 to 14 V
        Ignition switch ON with differential lock control switch OFF About 0 V

        Tech Tips

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

  3. CHECK 4 WHEEL DRIVE CONTROL ECU NO.2

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    1. Inspect the system circuit with the connector connected.


      1. Turn the ignition switch to the ON position.

      2. Shift the transfer shift lever to L position.

      3. Using a voltmeter, measure the voltage when the differential lock control switch is in the position, as shown in the table.

        Standard voltage:
        Tester connection Switch position Specified value
        4WD - GND - 0.5 V or less
        RLP - GND

        ON*

        		0.5 V or less
        M1 - M2 OFF → ON 0.5 V or less → 10 to 14 V (approx. 1 sec.) → 0.5 V or less
        M2 - M1 ON → OFF

        Tech Tips

        *The rear differential should be locked mechanically.


        • If the circuit is not as specified value, replace the ECU.

      4. Install the ECU in place.

  4. INSPECT DIFFERENTIAL LOCK COMPONENTS


    1. 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 the differential lock has occurred.

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        • If the operation is not as specified, replace the actuator.