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

A01BAWSE02

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. INSPECT ECM (+B VOLTAGE)


    1. A01BDCLE24

      Turn the ignition switch to ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      +B (B9-1) - E1 (D3-7) 11 to 14 V

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

    NG

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


    1. A01BFM0E91

      Disconnect the D3 ECM connector.

    2. Check the resistance.

      Standard resistance
      Tester Connection Specified Condition
      E1 (D3-7) - Body ground Below 1 Ω

    3. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT ECM (IGSW VOLTAGE)


    1. A01BDCLE25

      Turn the ignition switch to ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      IGSW (B9-9) - E1 (D3-7) 11 to 14 V

    OK

    INSPECT ECM (MREL VOLTAGE) Click here

    NG

  4. INSPECT FUSE (IGN FUSE)


    1. A01BGU3E01

      Remove the IGN fuse from the instrument panel J/B.

    2. Measure the IGN fuse resistance.

      Standard resistance
      Below 1 Ω

    3. Reinstall the IGN fuse.


    NG

    CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE, AND REPLACE FUSE

    OK

  5. INSPECT IGNITION SWITCH


    1. A01BCGXE50

      Disconnect the H25 ignition switch connector.

    2. Measure the ignition switch resistance.

      Standard resistance
      Tester Connection Switch Condition Specified Condition
      AM2 (7) - IG2 (6) LOCK 10 kΩ or higher
      AM2 (7) - IG2 (6) 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)

  6. INSPECT ECM (MREL VOLTAGE)


    1. A01BDCLE26

      Turn the ignition switch to ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      MREL (B9-8) - E1 (D3-7) 11 to 14 V

    NG

    REPLACE ECM

    OK

  7. INSPECT FUSE (EFI FUSE)


    1. A01BHEHE02

      Remove the EFI fuse from the No.1 engine room R/B and J/B.

    2. Measure the EFI fuse resistance.

      Standard resistance
      Below 1 Ω

    3. Reinstall the EFI fuse.


    NG

    CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE, AND REPLACE FUSE

    OK

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


    1. A01BEKUE26

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

    2. Check the integration relay resistance.

      Standard resistance
      Tester Connection Specified Condition
      1J-4 - 1K-1 10 kΩ or higher

      Below 1 Ω

      (when battery voltage applied to terminals 1J-2 and 1J-3)

    3. Reinstall the integration relay.


    NG

    REPLACE INTEGRATION NO.1 RELAY (MAIN RELAY)

    OK

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


    1. A01BEGCE01

      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 B9 ECM connector.

      3. Check the resistance.

        Standard resistance (Check for open)
        Tester Connection Specified Condition
        Integration relay (1J-2) - MREL (B9-8) Below 1 Ω
        Standard resistance (Check for short)
        Tester Connection Specified Condition
        Integration relay (1J-2) or MREL (B9-8) - Body ground 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. Check the resistance.

        Standard resistance (Check for open)
        Tester Connection Specified Condition
        Integration relay (1J-3) - Body ground 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)