DIFFERENTIAL SYSTEM (w/ Differential Lock) > INSPECTION

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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.
      

      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 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.
      

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

      HINT:

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

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

      HINT:

      ^*The rear differential should be locked mechanically.

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

   4. Install the ECU in place.
      

1. Inspect the relay operation.
   
   

   1. Jack up the vehicle.
      

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

      NOTICE:

      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.
      
      

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