MIL Circuit: Wiring Diagram

Fig 1: MIL Circuit - Wiring Diagram

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

Troubleshoot each trouble symptom in accordance with the chart below.

1. CHECK WHETHER MIL TURNS OFF 
   1. Connect the intelligent tester to the DLC3.
   2. Turn the ignition switch ON.
   3. Turn the tester ON.
   4. Check whether any DTCs have been stored (See DTC CHECK / CLEAR  ). Note them down if necessary.
   5. Clear DTCs (See DTC CHECK / CLEAR  ).
   6. Check if the MIL turns off.

      OK: 

      MIL should turn off. 

   OK: REPAIR CIRCUIT INDICATED BY OUTPUT DTC 

   NG: GO TO NEXT STEP 

2. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS) 
   1. Disconnect the H29 HV Control ECU connector.
   2. Turn the engine switch on (IG).
   3. Check the MIL is not illuminated.

      OK: 

      MIL is not illuminated. 

   4. Reconnect the HV Control ECU connector.
      Fig 2: Identifying H29 HV Control ECU Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: REPLACE HV CONTROL ECU 

   NG: CHECK AND REPAIR HARNESS AND CONNECTOR (COMBINATION METER - HV CONTROL ECU) 

3. CHECK THAT MIL IS ILLUMINATED 
   1. Check if the MIL is illuminated when the engine switch is turned to on.

      OK: 

      MIL should be illuminated. 

   OK: SYSTEM OK 

   NG: GO TO NEXT STEP 

4. INSPECT COMBINATION METER ASSEMBLY (MIL CIRCUIT) 
   1. See HOW TO PROCEED WITH TROUBLESHOOTING .

   NG: REPAIR OR REPLACE BULB OR COMBINATION METER ASSEMBLY 

   OK: CHECK AND REPAIR HARNESS AND CONNECTOR (COMBINATION METER - HV CONTROL ECU)