SFI SYSTEM MIL Circuit

DESCRIPTION

The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunctions detected by the ECM. When the engine switch is turned to on (IG), power is supplied to the MIL circuit, and the ECM provides the circuit ground which illuminates the MIL.

The MIL operation can be checked visually: When the engine switch is turned to on (IG), the MIL should be illuminated and should turn off after engine is started. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using the GTS.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK THAT MIL IS ILLUMINATED

   
   

   1. Perform troubleshooting in accordance with the table below.

      Result
      Condition Result Proceed to MIL remains ON Engine switch on (IG) → engine is started A MIL does not illuminate Engine switch on (IG) → engine is started (sometimes does not start) B MIL ON → MIL OFF Engine switch on (IG) → engine is started C

   
   

   B

   CHECK THAT ENGINE STARTS Click here

   C

   CHECK FOR INTERMITTENT PROBLEMS Click here

   A

2. CHECK WHETHER DTC OUTPUT RECURS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Enter the following menus: System Select / Health Check.

   5. Read the DTCs using the GTS.

      Result
      Result Proceed to DTCs is output A DTCs are not output B

      Tech Tips

      Check for detected DTCs output from other ECUs which relate to the MIL.

   
   

   A

   GO TO DTC CHART

   B

3. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)

   
   
   1. 

      *a	Front view of wire harness connector (to Network Gateway ECU)

      Disconnect the A118 gateway ECU connector.

   2. Turn the engine switch on (IG).

   3. Check that the MIL is not illuminated.

      OK
      MIL is not illuminated.

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE NETWORK GATEWAY ECU Click here

   NG

4. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - NETWORK GATEWAY ECU)

   
   

   1. Disconnect the F1 combination meter assembly connector.

   2. Disconnect the A118 network gateway ECU connector.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition F1-11 (CHK) or A118-21 (W) - Body ground and other terminals Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE COMBINATION METER ASSEMBLY Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

5. CHECK THAT ENGINE STARTS

   
   

   1. Turn the engine switch on (IG).

   2. Start the engine.

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

      Tech Tips

      *: The GTS cannot communicate with the ECM.

   
   

   B

   GO TO VC OUTPUT CIRCUIT Click here

   A

6. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY VOLTAGE)

   
   

   1. Disconnect the F1 combination meter assembly connector.

   2. Turn the engine switch on (IG).

   3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition F1-39 (IG+) - Body ground Engine switch on (IG) 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

7. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - NETWORK GATEWAY ECU)

   
   

   1. Disconnect the F1 combination meter assembly connector.

   2. Disconnect the A118 network gateway ECU connector.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition F1-11 (CHK) - A118-21 (W) Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE COMBINATION METER ASSEMBLY Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR