ECD SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, 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

A01CI7IE05

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. CHECK ECM (+B VOLTAGE)


    1. A01CHARE01
      Text in Illustration
      *1

      Component with harness connected

      (ECM)

      Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      E25-1 (+B) - E23-7 (E1) Ignition switch ON 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) Click here

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

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


    1. 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. A01CHARE02
      Text in Illustration
      *1

      Component with harness connected

      (ECM)

      Turn the ignition switch to ON.

    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 ON 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 No battery voltage applied to terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage 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. 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
      Standard Resistance (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. 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. 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
      Standard Resistance (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 SUB-ASSEMBLY)


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

    2. Disconnect the voltage converter sub-assembly 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
      Standard Resistance (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 sub-assembly connector.


    NG

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

    OK

    CHECK VOLTAGE CONVERTER SYSTEM

  9. CHECK ECM (IGSW VOLTAGE)


    1. A01CHARE03
      Text in Illustration
      *1

      Component with harness connected

      (ECM)

      Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      E25-16 (IGSW) - Body ground Ignition switch ON 11 to 14 V

    NG

    CHECK ENG-2 RELAY (VOLTAGE) Click here

    OK

    REPLACE ECM Click here

  10. CHECK ENG-2 RELAY (VOLTAGE)


    1. A01CIZPE02
      Text in Illustration
      *1 No. 1 Relay Block

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

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      ENG-2 relay terminal 1 - Body ground Ignition switch ON 18 to 27 V

    4. Reinstall the ENG-2 relay.


    NG

    INSPECT IGNITION SWITCH ASSEMBLY Click here

    OK

  11. 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 No battery voltage applied to terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage applied to terminals 1 and 2 Below 1 Ω

    3. Reinstall the ENG-2 relay.


    NG

    REPLACE ENG-2 RELAY

    OK

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


    1. 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
      Standard Resistance (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

  13. CHECK HARNESS AND CONNECTOR (ENG-2 RELAY - VOLTAGE CONVERTER SUB-ASSEMBLY)


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

    2. Disconnect the voltage converter sub-assembly 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
      Standard Resistance (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 sub-assembly connector.


    NG

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

    OK

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


    1. 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

  15. INSPECT IGNITION SWITCH ASSEMBLY


    1. A01CHNME17
      Text in Illustration
      *1

      Component without harness connected

      (Ignition Switch Assembly)

      Disconnect the ignition switch assembly connector.

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

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

    3. Reconnect the ignition switch assembly connector.


    NG

    REPLACE IGNITION SWITCH ASSEMBLY

    OK

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


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

    2. Disconnect the ignition switch assembly 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 assembly connector.


    NG

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

    OK

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