Inspection Procedure

HINT:

Check the condition of each related circuit connector before troubleshooting (see HOW TO PROCEED WITH TROUBLESHOOTING ).

1. CHECK FOR DTC 
   1. Check the output DTC (see DTC CHECK / CLEAR  ).

      Result 

      RESULT REFERENCE
      
      

      Result	Proceed to
      Neither CAN communication system DTC nor 4WD control system DTC is output	A
      CAN communication DTC is output	B
      4WD control system DTC is output	C

      HINT:

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

   B: REPAIR CIRCUIT INDICATOR BY OUTPUT CODE (CAN COMMUNICATION SYSTEM) 

   C: REPAIR CIRCUIT INDICATOR BY OUTPUT CODE (4WD CONTROL SYSTEM) 

   A: Go to next step 

2. PERFORM ACTIVE TEST BY TECHSTREAM (4WD INDICATOR LIGHT) 
   1. Using the Techstream Active Test, generate a control command, and then check that the 4WD indicator light operates.

      Combination Meter 

      ACTIVE TEST DETAIL
      
      

      Tester Display	Test Part	Control Range	Diagnostic Note
      4WD warn light	4WD indicator light	Indicator light is ON / OFF	Observer combination meter

      OK: 

      The 4WD indicator light turns OFF 

   OK: REPLACE 4WD CONTROL ECU 

   NG: Go to next step 

3. CHECK WIRE HARNESS (4WD CONTROL ECU - BATTERY) 
   1. Disconnect the E57 ECU connector.
   2. Measure the voltage of the wire harness side connector.

      Voltage 

      VOLTAGE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      E57-11 (IG1) - Body Ground	Ignition switch ON	10 to 14 V

      Fig 1: Identifying E57 4WD Control ECU Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

   OK: Go to next step 

4. CHECK COMBINATION METER 
   1. Check the combination meter system.

      Result: 

      The combination meter system is normal. 

   NG: REPLACE COMBINATION METER 

   OK: REPLACE 4WD CONTROL ECU