СИСТЕМА ECD 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 first turned to ON, the MIL should be illuminated and should then turn off when the engine is started. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using the GTS.

WIRING DIAGRAM

A01IO9JE01

INSPECTION PROCEDURE

Note


  • When replacing the ECM, the ECM needs Registration and Initialization Click here.

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

Tech Tips

When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing the new ECM, perform all of the initialization/registrations for the "Learning Values Write" function by following the instructions shown on the GTS display.

PROCEDURE


  1. CHECK THAT MIL IS ILLUMINATED


    1. Perform troubleshooting in accordance with the table below.

      Result
      Result Proceed to
      MIL remains on A
      MIL does not illuminate B

    B

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

    A

  2. CHECK WHETHER MIL TURNS OFF


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

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

    4. Clear DTCs Click here.

    5. Check that the MIL turns off.

      OK
      MIL turns off.

    NG

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

    OK

    REPLACE CIRCUITS INDICATED BY OUTPUT DTCS

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


    1. A01IRFQE64
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

    2. Turn the ignition switch to ON.

    3. Check that MIL is not illuminated.

      OK
      MIL is not illuminated.

    NG

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

    OK

    REPLACE ECM Click here

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


    1. Disconnect the ECM connector.

    2. Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H62-29 (EFI) or A76-59 (W) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

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


    1. Disconnect the ECM connector.

    2. Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H62-29 (EFI) - A76-59 (W) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here