SFI SYSTEM MIL Circuit

DESCRIPTION

The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunction detections by the ECM. By turning the engine switch 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 first turned on (IG), the MIL should be illuminated and should then turn off. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure.

If the ECM detects trouble, the MIL illuminates. At this time, the ECM records a DTC in the memory.

WIRING DIAGRAM

A01GNX0E16

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK THAT MIL IS ILLUMINATED


    1. Perform troubleshooting in accordance with the chart below.

      Result
      Condition Proceed to
      MIL remains on A
      MIL is not illuminated B

    B

    CHECK THAT MIL IS ILLUMINATED Click here

    A

  2. CHECK IF MIL TURNS OFF


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) and turn the tester ON.

    3. Check if DTCs have been stored Click here. If DTCs are present, write them down.

    4. Clear the DTCs Click here.

    5. Check that the MIL turns off.

      OK
      MIL turns off.

    OK

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

    NG

  3. CHECK HARNESS AND CONNECTOR (FOR SHORT)

    A01GM1ME02

    1. Disconnect the A14 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 - ECM)

    A01GIUME06

    1. Disconnect the L10 combination meter connector.

    2. Disconnect the A14 ECM connector.

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

      Standard resistance (check for open)
      Tester Connection Condition Specified Condition
      L10-11 (EFI) - A14-11 (W) Always Below 1 Ω
      Standard resistance (check for short)
      Tester Connection Condition Specified Condition
      L10-11 (EFI) or A14-11 (W) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE NO. 1 METER ECU Click here

  5. CHECK THAT MIL IS ILLUMINATED


    1. Check that the MIL is illuminated when turning the engine switch on (IG).

      OK
      MIL is illuminated.

    OK

    SYSTEM OK

    NG

  6. 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 intelligent tester cannot communicate with the ECM.


    B

    GO TO VC OUTPUT CIRCUIT Click here

    A

  7. INSPECT COMBINATION METER ASSEMBLY (MIL CIRCUIT)


    1. See the combination meter troubleshooting procedure Click here.


    NG

    REPLACE NO. 1 METER ECU Click here

    OK

    CHECK AND REPLACE HARNESS OR CONNECTOR (COMBINATION METER - ECM)