MIL Circuit: Procedure

1. Perform troubleshooting in accordance with the table below:

   Result

   Conditions	Proceed to
   MIL remains ON	A
   MIL does not illuminate	B

B → See step   5 

A: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG) and turn the Techstream on.
3. Select the following menu items: Powertrain / Engine / Trouble Code.
4. Check if any DTCs have been stored. Note down any DTCs.
5. Clear the DTCs. Refer to DTC CHECK / CLEAR .
6. Check if the MIL goes off.

   Standard

   MIL goes off.

OK → See step   8 

NG: Go to next step 

1. Disconnect the A10 ECM connector.
   Fig 1: Identifying A10 ECM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the engine switch on (IG).
3. Check that the MIL is not illuminated.

   OK

   MIL is not illuminated.

4. Reconnect the ECM connector.

OK → See step   9 

NG: Go to next step 

1. Disconnect the A10 ECM connector.
   Fig 2: Identifying ECM Connector Terminals & Combination Meter Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the E20 combination meter connector.
3. Measure the resistance.

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   A10-24 (W) or E20-4 (CHK) - Body ground	10 kΩ or higher

4. Reconnect the ECM connector.
5. Reconnect the combination meter connector.

OK → REPAIR OR REPLACE COMBINATION METER ASSEMBLY 

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Check if the MIL is illuminated when the engine switch is turned on (IG).

   OK

   MIL is illuminated.

OK → SYSTEM OK 

NG: Go to next step 

1. Turn the engine switch on (IG).
2. Start the engine.

   Result

   Result	Proceed to
   Engine starts	A
   Engine does not start*	B

   HINT: 

   *: Techstream cannot communicate with the ECM.

B → See step   10 

A: Go to next step 

1. Check the MIL circuit. Refer to HOW TO PROCEED WITH TROUBLESHOOTING .

NG → REPAIR OR REPLACE COMBINATION METER ASSEMBLY 

OK → CHECK AND REPLACE HARNESS AND CONNECTOR (COMBINATION METER - ECM)