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 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 registration Click here and initialization Click here.

PROCEDURE


  1. CHECK ECM (+B VOLTAGE)


    1. A01DZAPE15

      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) 11 to 14 V

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS TABLE

    NG

  2. CHECK WIRE HARNESS (ECM - BODY GROUND)


    1. A01DZYRE87

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

    OK

  3. CHECK ECM (IGSW VOLTAGE)


    1. A01DZAPE17

      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) 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 junction block.

    2. Measure the resistance of the fuse.

      Standard resistance
      Below 1 Ω

    NG

    CHECK FOR SHORT IN ALL HARNESSES 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 OR CONNECTOR (BATTERY - IGNITION SWITCH, IGNITION SWITCH - ECM)

  6. CHECK ECM (MREL VOLTAGE)


    1. A01DZAPE18

      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) 11 to 14 V

    NG

    REPLACE ECM

    OK

  7. INSPECT FUSE (EFI FUSE)


    1. A01DXVCE11

      Remove the EFI fuse from the engine room junction block.

    2. Measure the resistance of the fuse.

      Standard resistance
      Below 1 Ω

    NG

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

    OK

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


    1. A01DZ2WE23

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

    2. Disconnect the 1J No. 1 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 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (MAIN RELAY) - ECM, INTEGRATION RELAY (MAIN RELAY) - BODY GROUND) Click here

    OK

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


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

    2. A01DYFWE13

      Disconnect the 1J No. 1 integration relay connector from the engine room junction block.

    3. Disconnect the E5 ECM connector.

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

      Standard resistance (Check for open)
      Tester Connection Specified Condition
      1J-4 - E5-1 (+B) Below 1 Ω
      1J-3 - Body ground Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Specified Condition
      1J-4 or E5-1 (+B) - 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)

  10. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (MAIN RELAY) - ECM, INTEGRATION RELAY (MAIN RELAY) - BODY GROUND)


    1. A01DYFWE14

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

    2. Disconnect the 1J No. 1 integration relay connector from the engine room junction block.

    3. Disconnect the E5 ECM connector.

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

      Standard resistance (Check for open)
      Tester Connection Specified Condition
      1J-2 - E5-8 (MREL) Below 1 Ω
      1J-3 - Body ground Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Specified Condition
      1J-2 or E5-8 (MREL) - Body ground 10 kΩ or higher

    NG

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

    OK

    REPLACE NO.1 INTEGRATION RELAY