Inspection Procedure

Check the condition of each related circuit connector before troubleshooting (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).

1. CHECK CAN COMMUNICATION SYSTEM 
   1. Check if the CAN communication system DTC is output.

      Result 

      RESULT REFERENCE CHART
      
      

      Result	Proceed to
      DTC is not output	A
      DTC is output	B

      HINT:

      When DTCs indicating a CAN communication system malfunction are output, repair the CAN communication system before repairing each corresponding sensor.

      B: REPAIR CAN COMMUNICATION SYSTEM  (See DIAGNOSTIC TROUBLE CODE CHART )

      A: Go to Next Step 

2. INSPECT 4WD WARNING LIGHT 
   1. Disconnect the 4WD control ECU connector.
   2. Turn the ignition switch to ON.
      Fig 1: Inspecting 4WD Control ECU Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Check that the 4WD warning light comes on.

      OK: 

      4WD warning light comes on  .

      NG: REPLACE COMBINATION METER  (See COMBINATION METER )

      Fig 2: Checking 4WD Warning Light Comes On

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: REPLACE 4WD CONTROL ECU  (See REMOVAL  )