ECD SYSTEM (w/ 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

A01E0YYE07

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. CHECK ECM (+B VOLTAGE)


    1. A01DV1IE28

      Turn the ignition switch ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      +B (E5-1) - E1 (E7-7) 11 to 14 V

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

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


    1. A01DZYRE92

      Disconnect the E7 ECM connector.

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

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK ECM (IGSW VOLTAGE)


    1. A01DV1IE29

      Turn the ignition switch ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      IGSW (E5-9) - E1 (E7-7) 11 to 14 V

    OK

    CHECK ECM (MREL VOLTAGE) Click here

    NG

  4. INSPECT FUSE (IGN FUSE)


    1. A01DXM3E01

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

    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

  6. CHECK ECM (MREL VOLTAGE)


    1. A01DV1IE30

      Turn the ignition switch ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      MREL (E5-8) - E1 (E7-7) 11 to 14 V

    NG

    REPLACE NO.1 INTEGRATION RELAY Click here

    OK

  7. INSPECT FUSE (EFI FUSE)


    1. A01E1UOE01

      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 NO.1 INTEGRATION RELAY (MAIN RELAY)


    1. A01DZ2WE22

      Remove the No. 1 integration relay from the engine room junction block Click here.

    2. Measure the voltage of the No. 1 integration relay

      Standard voltage
      Tester Connection Condition Specified Condition
      1J-4 - Body ground Ignition switch ON 11 to 14 V

    NG

    REPLACE NO.1 INTEGRATION RELAY Click here

    OK

  9. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (MAIN RELAY) - ECM)


    1. A01DYFWE13

      Disconnect the 1J No. 1 integration relay connector from the engine room J/B Click here.

    2. Disconnect the E5 ECM connector.

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

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 INTEGRATION RELAY (MAIN RELAY) - ECM)

    OK

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