SFI SYSTEM MIL Circuit

DTC Code DTC Name
MIL Circuit

DESCRIPTION

The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunctions detected 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 turned to ON, 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

A357474E01
A298565E39

PROCEDURE

  1. CHECK THAT MIL IS ILLUMINATED

    1. Perform troubleshooting in accordance with the table below.

    Result

    Condition

    Result

    Proceed to

    MIL remains ON

    Ignition switch ON → engine is started

    A

    MIL does not illuminate

    Ignition switch ON → engine is started (sometimes does not start)

    B

    MIL ON → MIL OFF

    Ignition switch ON → engine is started

    C
    B

    CHECK THAT ENGINE STARTSClick 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 ignition switch to ON.

    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
    Tip:

    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. A354321C05

      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the A173 ECM connector.

    2. Turn the ignition switch to ON.

    3. Check that the MIL is not illuminated.

      OK

      MIL is not illuminated.

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE ECM

    Click hereClick 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

      E46-11 (CHK) or A173-27 (W) - Body ground

      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 ignition switch to ON.

    2. Start the engine.

      Result

      Result

      Proceed to

      Engine starts

      A

      Engine does not start*

      B
      Tip:

      *: The GTS cannot communicate with the ECM.

    B

    GO TO VC OUTPUT CIRCUIT

    Click hereClick here

    A

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

    1. Disconnect the combination meter assembly connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      E46-39 (IG+) - Body ground

      Ignition switch ON

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    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

      E46-11 (CHK) - A173-27 (W)

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE COMBINATION METER ASSEMBLY

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR