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 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 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

A01VZ6ZE04

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

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 are not output A
      DTCs are output B

      Tech Tips

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


    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

    A

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


    1. A01W1CBE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the A75 ECM connector.

    2. Turn the engine switch on (IG).

    3. Check that the MIL is not illuminated.

      OK
      MIL is not illuminated.

    OK

    REPLACE ECM Click here

    NG

  4. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)


    1. Disconnect the combination meter assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H14-10 (CEK) or A75-27 (W) - Body ground or other terminals Always 10 kΩ or higher

    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 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
      H14-21 (IG+) - Body ground Engine switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  7. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)


    1. Disconnect the combination meter assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H14-10 (CHK) - A75-27 (W) Always Below 1 Ω

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR