ECD SYSTEM (w/o EGR Cooler) ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned ON, the battery voltage is applied to terminal IGSW of the ECM. The ECM "MREL" output signal 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

A01E1XQE02

INSPECTION PROCEDURE

Note

If the ECM is replaced, the new ECM needs initialization Click here.

PROCEDURE


  1. CHECK ECM (+B VOLTAGE)


    1. A01E2OGE34

      Turn the ignition switch ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      E5-1 (+B) - E7-7 (E1) 9 to 14 V

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS TABLE

    NG

  2. CHECK WIRE HARNESS (ECM - BODY GROUND)


    1. A01DZYRE08

      Disconnect the E7 ECM connector.

    2. Measure the resistance of the wire harness side connector.

      Standard resistance
      Tester Connection Specified Condition
      E7-7 (E1) - Body ground Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  3. CHECK ECM (IGSW VOLTAGE)


    1. A01E2OGE35

      Turn the ignition switch ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      E5-9 (IGSW) - E7-7 (E1) 9 to 14 V

    OK

    CHECK ECM (MREL VOLTAGE) Click here

    NG

  4. INSPECT FUSE (IGN FUSE)


    1. A01E1DOE01

      Remove the IGN fuse from the instrument panel junction block.

    2. Measure the resistance of the fuse.

      Standard resistance
      Below 1 Ω

    NG

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

    OK

  5. INSPECT IGNITION SWITCH ASSEMBLY


    1. A01DV3BE52

      Disconnect the I6 ignition switch connector.

    2. Measure the resistance of the ignition switch.

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

    NG

    REPLACE IGNITION SWITCH ASSEMBLY

    OK

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

  6. CHECK ECM (MREL VOLTAGE)


    1. A01E2OGE36

      Turn the ignition switch ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      E5-8 (MREL) - E7-7 (E1) 9 to 14 V

    NG

    REPLACE ECM Click here

    OK

  7. INSPECT FUSE (EFI FUSE)


    1. A01DXVCE09

      Remove the EFI fuse from the engine room junction block.

    2. Measure the resistance of the fuse.

      Standard resistance
      Below 1 Ω

    NG

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

    OK

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


    1. A01DZ2WE07

      Remove the integration relay from the engine room junction block Click here.

    2. Disconnect the 1J integration relay connector.

    3. Measure the voltage of the MAIN relay.

      Standard voltage
      Tester Connection Condition Specified Condition
      1J-4 - Body ground Ignition switch ON 10 to 14 V

    NG

    REPLACE INTEGRATION NO.1 RELAY

    OK

  9. CHECK WIRE HARNESS (INTEGRATION RELAY (MAIN RELAY) - ECM)


    1. A01DYFWE02

      Disconnect the 1J integration relay connector from the engine room junction block Click here.

    2. Disconnect the E5 ECM connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      1J-4 - E5-1 (+B) Below 1 Ω
      1J-4 or E5-1 (+B) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM)

    OK

    REPAIR OR REPLACE HARNESS AND CONNECTOR (+B TERMINAL OF ECM - BATTERY POSITIVE TERMINAL)