ECD SYSTEM (w/o 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

A01BB28E01

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 VOLTAGE)


    1. A01BF7WE57
      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) Always 11 to 14 V

    NG

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

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

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


    1. Disconnect the D70 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. A01BF7WE58
      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. A01BF7WE59
      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

    OK

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


    1. A01BEKUE48
      Text in Illustration
      *1 Integration Relay
      *a Fuse Side
      *b Connector Side

      Remove the integration relay from the No. 1 engine room R/B and J/B.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1J-4 - 1K-1 When battery voltage is not applied to terminals 1J-2 and 1J-3 10 kΩ or higher
      When battery voltage is applied to terminals 1J-2 and 1J-3 Below 1 Ω

    3. Reinstall the integration relay.


    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 integration relay (MAIN relay) and ECM.


      1. Remove the integration relay (MAIN relay) from the No. 1 engine room R/B and J/B.

      2. Disconnect the B47 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
        1J-2 - B47-11 (MREL) Always Below 1 Ω
        Standard Resistance (Check for Short)
        Tester Connection Condition Specified Condition
        1J-2 or B47-11 (MREL) - Body ground Always 10 kΩ or higher

      4. Reconnect the ECM connector.

      5. Reinstall the integration relay.

    2. Check the harness and connector between the integration relay (MAIN relay) and body ground.


      1. Remove the integration relay (MAIN relay) from the No. 1 engine room R/B and J/B.

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

        Standard Resistance (Check for Open)
        Tester Connection Condition Specified Condition
        1J-3 - Body ground Always Below 1 Ω

      3. Reinstall the integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (TERMINAL +B OF ECM - MAIN RELAY)

  7. INSPECT IGNITION SWITCH


    1. A01BCGXE58
      Text in Illustration
      *1 Ignition Switch

      Disconnect the H25 ignition switch connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      7 (AM2) - 6 (IG2) LOCK 10 kΩ or higher
      7 (AM2) - 6 (IG2) ON Below 1 Ω

    3. Reconnect the ignition switch connector.


    NG

    REPLACE IGNITION SWITCH

    OK

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