ECD SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to the ON position, 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 ENG-3 relay and supplying power to terminal +B of the ECM.

WIRING DIAGRAM

A01CI7IE04

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK ECM (+B VOLTAGE)


    1. A01CGXCE16

      Turn the ignition switch to the ON position.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      E25-1 (+B) - E23-7 (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. A01CJ1DE01

      Disconnect ECM connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      E23-7 (E1) - Body ground Always Below 1 Ω

    3. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND)

    OK

  3. CHECK ECM (MREL VOLTAGE)


    1. A01CGXCE17

      Turn the ignition switch to the ON position.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      E25-13 (MREL) - Body ground Ignition switch in the ON position 11 to 14 V

    NG

    CHECK ECM (IGSW VOLTAGE) Click here

    OK

  4. INSPECT ENG-3 RELAY


    1. A01CGY9E02

      Remove the ENG-3 relay from the No. 1 relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      3 - 5 Battery voltage is not applied to terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage is applied to terminals 1 and 2 Below 1 Ω

    3. Reinstall the ENG-3 relay.


    NG

    REPLACE ENG-3 RELAY

    OK

  5. CHECK HARNESS AND CONNECTOR (ENG-3 RELAY - ECM)


    1. A01CHZAE01

      Remove the ENG-3 relay from the No. 1 relay block.

    2. Disconnect the 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
      ENG-3 relay terminal 3 - E25-1 (+B) Always Below 1 Ω
      Check for short
      Tester Connection Condition Specified Condition
      ENG-3 relay terminal 3 or E25-1 (+B) - Body ground Always 10 kΩ or higher

    4. Reinstall the ENG-3 relay.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENG-3 RELAY - ECM)

    OK

  6. CHECK HARNESS AND CONNECTOR (ENG-3 RELAY - BODY GROUND)


    1. A01CHSDE01

      Remove the ENG-3 relay from the No. 1 relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      ENG-3 relay terminal 2 - Body ground Always Below 1 Ω

    3. Reinstall the ENG-3 relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENG-3 RELAY - BODY GROUND)

    OK

  7. CHECK HARNESS AND CONNECTOR (ECM - ENG-3 RELAY)


    1. A01CHZAE02

      Remove the ENG-3 relay from the No. 1 relay block.

    2. Disconnect the 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
      E25-13 (MREL) - ENG-3 relay terminal 1 Always Below 1 Ω
      Check for short
      Tester Connection Condition Specified Condition
      E25-13 (MREL) or ENG-3 relay terminal 1 - Body ground Always 10 kΩ or higher

    4. Reinstall the ENG-3 relay.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - ENG-3 RELAY)

    OK

  8. CHECK HARNESS AND CONNECTOR (ENG-3 RELAY - VOLTAGE CONVERTER)


    1. A01CHOFE01

      Remove the ENG-3 relay from the No. 1 relay block.

    2. Disconnect the voltage converter connector.

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

      Standard resistance
      Check for open
      Tester Connection Condition Specified Condition
      ENG-3 relay terminal 5 - D8-2 (OUT1) Always Below 1 Ω
      ENG-3 relay terminal 5 - D8-8 (OUT2) Always Below 1 Ω
      Check for short
      Tester Connection Condition Specified Condition
      ENG-3 relay terminal 5 or D8-2 (OUT1) - Body ground Always 10 kΩ or higher
      ENG-3 relay terminal 5 or D8-8 (OUT2) - Body ground Always 10 kΩ or higher

    4. Reinstall the ENG-3 relay.

    5. Reconnect the voltage converter connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENG-3 RELAY - VOLTAGE CONVERTER)

    OK

    CHECK VOLTAGE CONVERTER SYSTEM

  9. CHECK ECM (IGSW VOLTAGE)


    1. A01CGXCE18

      Turn the ignition switch to the ON position.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      E25-16 (IGSW) - Body ground Ignition switch in the ON position 11 to 14 V

    NG

    CHECK ENG-2 RELAY (VOLTAGE) Click here

    OK

    REPLACE ECM

  10. CHECK ENG-2 RELAY (VOLTAGE)


    1. A01CIZPE01

      Remove the ENG-2 relay from the No. 1 relay block.

    2. Turn the ignition switch to the ON position.

    3. Measure the voltage according to the value(s) in the table below.

      Standard voltage
      Tester Connection Condition Specified Condition
      ENG-2 relay terminal 1 - Body ground Ignition switch in the ON position 11 to 14 V

    4. Reinstall the ENG-2 relay.


    NG

    INSPECT FUSE (AM2 FUSE) Click here

    OK

  11. INSPECT FUSE (ENG FUSE)


    1. A01CGKEE01

      Remove the ENG fuse from the No. 1 relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      1 - 2 Always Below 1 Ω

    3. Reinstall the ENG fuse.


    NG

    REPLACE FUSE (ENG FUSE)

    OK

  12. INSPECT ENG-2 RELAY


    1. A01CJEC

      Remove the ENG-2 relay from the No. 1 relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      3 - 5 Always 10 kΩ or higher
      3 - 5 Always

      below 1 Ω

      (when battery voltage is applied to terminals 1 and 2)

    3. Reinstall the ENG-2 relay.


    NG

    REPLACE ENG-2 RELAY

    OK

  13. CHECK HARNESS AND CONNECTOR (ENG-2 RELAY - ECM)


    1. A01CJD2E01

      Remove the ENG-2 relay from the No. 1 relay block.

    2. Disconnect the 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
      ENG-2 relay terminal 5 - E25-16 (IGSW) Always Below 1 Ω
      Check for short
      Tester Connection Condition Specified Condition
      ENG-2 relay terminal 5 or E25-16 (IGSW) - Body ground Always 10 kΩ or higher

    4. Reinstall the ENG-2 relay.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENG-2 RELAY - ECM)

    OK

  14. CHECK HARNESS AND CONNECTOR (ENG-2 RELAY - VOLTAGE CONVERTER)


    1. A01CGT2E01

      Remove the ENG-2 relay from the No. 1 relay block.

    2. Disconnect the voltage converter connector.

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

      Standard resistance
      Check for open
      Tester Connection Condition Specified Condition
      ENG-2 relay terminal 3 - D8-2 (OUT1) Always Below 1 Ω
      ENG-2 relay terminal 3 - D8-8 (OUT2) Always Below 1 Ω
      Check for short
      Tester Connection Condition Specified Condition
      ENG-2 relay terminal 3 or D8-2 (OUT1) - Body ground Always 10 kΩ or higher
      ENG-2 relay terminal 3 or D8-8 (OUT2) - Body ground Always 10 kΩ or higher

    4. Reinstall the ENG-2 relay.

    5. Reconnect the voltage converter connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENG-2 RELAY - VOLTAGE CONVERTER)

    OK

  15. CHECK HARNESS AND CONNECTOR (ENG-2 RELAY - BODY GROUND)


    1. A01CIZPE01

      Remove the ENG-2 relay from the No. 1 relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      ENG-2 relay terminal 2 - Body ground Always Below 1 Ω

    3. Reinstall the ENG-2 relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENG-2 RELAY - BODY GROUND)

    OK

    CHECK VOLTAGE CONVERTER SYSTEM

  16. INSPECT FUSE (AM2 FUSE)


    1. A01CJF3E01

      Remove the AM2 fuse from the No. 1 relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      1 - 2 Always Below 1 Ω

    3. Reinstall the AM2 fuse.


    NG

    REPLACE FUSE (AM2 FUSE)

    OK

  17. INSPECT IGNITION SWITCH ASSEMBLY


    1. A01CHNME06

      Disconnect the ignition switch connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      I6-5 (AM2) - I6-8 (IG2) LOCK 10 kΩ or higher
      I6-5 (AM2) - I6-8 (IG2) ON Below 1 Ω

    3. Reconnect the ignition switch connector.


    NG

    REPLACE IGNITION SWITCH ASSEMBLY

    OK

  18. CHECK HARNESS AND CONNECTOR (ENG-2 RELAY - IGNITION SWITCH)


    1. A01CI48E01

      Remove the ENG-2 relay from the No. 1 relay block.

    2. Disconnect the ignition switch connector.

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

      Standard resistance
      Check for open
      Tester Connection Condition Specified Condition
      ENG-2 relay terminal 1 - I6-8 (IG2) Always Below 1 Ω
      Check for short
      Tester Connection Condition Specified Condition
      ENG-2 relay terminal 1 or I6-8 (IG2) - Body ground Always 10 kΩ or higher

    4. Reinstall the ENG-2 relay.

    5. Reconnect the ignition switch connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENG-2 RELAY - IGNITION SWITCH)

    OK

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