SFI SYSTEM MIL Circuit

DESCRIPTION

The MIL (Malfunction Indicator Lamp) is used to indicate the detection of vehicle malfunctions by the ECM. When the ignition switch is turned to ON, 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 ignition switch is first turned to ON, the MIL turns on and then off. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using the intelligent tester.

WIRING DIAGRAM

A00DPUEE02
A00DT8ME01

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. CHECK THAT MIL IS ILLUMINATED


    1. Turn the ignition switch to ON.

    2. Check the illumination condition of the MIL.

      Result
      Condition Proceed to
      MIL remains illuminated (Even after ignition switch turned to ON and several seconds have passed, MIL still remains illuminated) A
      MIL remains off (Does not illuminate at all) B
      MIL illuminates for several seconds, but turns off after engine is started C

    B

    CHECK THAT ENGINE STARTS Click here

    C

    SYSTEM OK

    A

  2. CHECK WHETHER MIL TURNS OFF


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / DTC.

    5. Check if any DTCs are output. Note down any DTCs.

    6. Clear the DTCs Click here.

    7. Check if the MIL goes off.

      OK
      MIL goes off.

    NG

    CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS) Click here

    OK

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

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


    1. A00DT9CE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

    2. Turn the ignition switch to ON.

    3. Check that the MIL is not illuminated.

      OK
      MIL is not illuminated.

    4. Reconnect the ECM connector.


    NG

    CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM) Click here

    OK

    REPLACE ECM Click here

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


    1. A00DTS0E44
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Combination Meter)
      *2

      Front view of wire harness connector

      (to ECM)

      Disconnect the combination meter connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D66-29 (EFI) or A40-24 (W) - Body ground Always 10 kΩ or higher

    4. Reconnect the combination meter connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER - ECM)

    OK

    REPLACE COMBINATION METER Click here

  5. CHECK THAT ENGINE STARTS


    1. Turn the ignition switch to ON.

    2. Check that the engine starts.

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

      Tech Tips

      *: The intelligent tester cannot communicate with the ECM.


    B

    GO TO VC OUTPUT CIRCUIT Click here

    A

  6. CHECK COMBINATION METER ASSEMBLY (COMBINATION METER - BODY GROUND)


    1. A00DT9CE04
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A40-24 (W) - Body ground Ignition switch ON 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM) Click here

    OK

    REPLACE ECM Click here

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


    1. A00DTS0E44
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Combination Meter)
      *2

      Front view of wire harness connector

      (to ECM)

      Disconnect the combination meter 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
      D66-29 (EFI) - A40-24 (W) Always Below 1 Ω

    4. Reconnect the ECM connector.

    5. Reconnect the combination meter connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER - ECM)

    OK

    REPLACE COMBINATION METER Click here