ECD SYSTEM (w/ DPF) ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, the battery voltage is applied to terminal IGSW of the ECM. The MREL output signal from ECM causes a current to flow to the coil, closing the contacts of the EFI MAIN relay and supplying power to terminal +B and +B2 of the ECM.

WIRING DIAGRAM

A01KEGYE03

INSPECTION PROCEDURE

Note


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

  • After replacing the ECM, the new ECM needs registration Click here and initialization Click here.

  • After replacing the fuel supply pump assembly, the ECM needs initialization Click here.

  • After replacing an injector assembly, the ECM needs registration Click here.

PROCEDURE


  1. INSPECT ECM (+B AND +B2 VOLTAGE)


    1. Turn the ignition switch to ON.

    2. A01KGHCE22
      Text in Illustration
      *a

      Component with harness connected

      (ECM)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      E17-24 (+B) - E10-1 (E1) Ignition switch ON 11 to 14 V
      E17-17 (+B2) - E10-1 (E1) Ignition switch ON 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) Click here

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  2. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)


    1. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E10-1 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT ECM (IGSW VOLTAGE)


    1. A01KGHCE23
      Text in Illustration
      *a

      Component with harness connected

      (ECM)

      Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      E16-24 (IGSW) - E10-1 (E1) Ignition switch ON 11 to 14 V

    NG

    INSPECT IGNITION SWITCH ASSEMBLY Click here

    OK

  4. INSPECT ECM (MREL VOLTAGE)


    1. A01KGHCE24
      Text in Illustration
      *a

      Component with harness connected

      (ECM)

      Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      E16-11 (MREL) - E10-1 (E1) Ignition switch ON 11 to 14 V

    NG

    REPLACE ECM Click here

    OK

  5. INSPECT EFI MAIN RELAY


    1. Remove the EFI MAIN relay from engine room relay block.

    2. A01KIHJE01

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Battery voltage not applied to terminals 1 and 2 10 kΩ or higher
      Battery voltage applied to terminals 1 and 2 Below 1 Ω

    NG

    REPLACE EFI MAIN RELAY

    OK

  6. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY HOLDER - ECM - BODY GROUND)


    1. Check the harness and connector between EFI MAIN relay and ECM.


      1. Remove the EFI MAIN relay from the engine room relay block.

      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
        EFI MAIN relay holder 3 - E17-24 (+B) Always Below 1 Ω
        EFI MAIN relay holder 3 - E17-17 (+B2) Always Below 1 Ω
        EFI MAIN relay holder 1 - E16-11 (MREL) Always Below 1 Ω
        EFI MAIN relay holder 3 or E17-24 (+B) - Body ground Always 10 kΩ or higher
        EFI MAIN relay holder 3 or E17-17 (+B2) - Body ground Always 10 kΩ or higher
        EFI MAIN relay holder 1 or E16-11 (MREL) - Body ground Always 10 kΩ or higher

    2. Check the harness and connector between the EFI MAIN relay and body ground.


      1. Remove the EFI MAIN relay from the engine room relay block.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        EFI MAIN relay holder 2 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - EFI MAIN RELAY)

  7. INSPECT IGNITION SWITCH ASSEMBLY


    1. Inspect the ignition switch assembly Click here.


    NG

    REPLACE IGNITION SWITCH ASSEMBLY Click here

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - IGNITION SWITCH ASSEMBLY - ECM)