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 MAIN relay and supplying power to terminal +B of the ECM.

WIRING DIAGRAM

A01BBDEE01

INSPECTION PROCEDURE

Note


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

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

PROCEDURE


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


    1. Turn the ignition switch to ON.

    2. A01BENLE27
      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 Condition Specified Condition
      B48-24 (+B) - D70-1 (E1) Ignition switch ON 11 to 14 V
      B48-17 (+B2) - D70-1 (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
      D70-1 (E1) - Body ground Always Below 1 Ω

    3. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT ECM (IGSW VOLTAGE)


    1. A01BENLE28
      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
      B47-24 (IGSW) - D70-1 (E1) Ignition switch ON 11 to 14 V

    NG

    INSPECT IGNITION SWITCH Click here

    OK

  4. INSPECT ECM (MREL VOLTAGE)


    1. A01BENLE29
      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
      B47-11 (MREL) - D70-1 (E1) Ignition switch ON 11 to 14 V

    NG

    REPLACE ECM Click here

    OK

  5. INSPECT NO. 1 INTEGRATION RELAY (MAIN RELAY)


    1. Inspect the No. 1 integration relay (MAIN relay) Click here.


    NG

    REPLACE INTEGRATION NO. 1 RELAY (MAIN RELAY)

    OK

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


    1. Check the harness and connector between the No. 1 integration relay (MAIN relay) and ECM.


      1. Remove the No. 1 integration relay from the engine room relay block and junction block assembly.

      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
        1M-4 - B48-24 (+B) Always Below 1 Ω
        1M-4 - B48-17 (+B2) Always Below 1 Ω
        1M-2 - B47-11 (MREL) Always Below 1 Ω
        1M-4 or B48-24 (+B) - Body ground Always 10 kΩ or higher
        1M-4 or B48-17 (+B2) - Body ground Always 10 kΩ or higher
        1M-2 or B47-11 (MREL) - Body ground Always 10 kΩ or higher

      4. Reconnect the ECM connector.

      5. Reinstall the No. 1 integration relay.

    2. Check the harness and connector between the No. 1 integration relay (MAIN relay) and body ground.


      1. Remove the No. 1 integration relay from the engine room relay block and junction block assembly.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        1M-3 - Body ground Always Below 1 Ω

      3. Reinstall the No. 1 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

  7. INSPECT IGNITION SWITCH


    1. Inspect the ignition switch Click here.


    NG

    REPLACE IGNITION SWITCH Click here

    OK

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