SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, the IGSW signal is input into the ECM. This turns the internal transistor ON, causing the current to flow to the EFI MAIN1 relay coil, which closes the relay, supplying power to the ECM +B and +B2 terminals.

WIRING DIAGRAM

A004J9SE02

CAUTION / NOTICE / HINT

Note


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

PROCEDURE


  1. INSPECT ECM (POWER SOURCE VOLTAGE)

    A004KHIE02
    Text in Illustration
    *a

    Component with harness connected

    (ECM)

    1. 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
      A34-6 (+B) - A36-4 (E01) Ignition switch ON 12 to 14 V
      A33-1 (+B2) - A36-4 (E01) Ignition switch ON 12 to 14 V

    NG

    INSPECT ECM (SSHUT TERMINAL VOLTAGE) Click here

    OK

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


    1. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A36-4 (E01) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT ECM (IGSW TERMINAL VOLTAGE)

    A004HHTE02
    Text in Illustration
    *a

    Component without harness connected

    (ECM)

    1. 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
      A33-27 (IGSW) - A36-4 (E01) Ignition switch ON 10 to 13 V

    OK

    REPLACE ECM Click here

    NG

    CHECK HARNESS AND CONNECTOR (IG2 RELAY - ECM) Click here

  4. INSPECT ECM (SSHUT TERMINAL VOLTAGE)

    A004K1NE02
    Text in Illustration
    *a

    Component without harness connected

    (ECM)

    1. 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
      A35-13 (SSHUT) - A36-4 (E01) Ignition switch ON approximately 0 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT RELAY (EFI MAIN1)


    1. Inspect the EFI MAIN1 relay Click here.


    NG

    REPLACE RELAY (EFI MAIN1)

    OK

  6. CHECK HARNESS AND CONNECTOR (EFI MAIN1 RELAY - ECM)


    1. Remove the EFI MAIN1 relay from the engine room relay block assembly.

    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
      EFI MAIN1 relay terminal 1 - A35-13 (SSHUT) Always Below 1 Ω
      EFI MAIN1 relay terminal 3 - A34-6 (+B) Always Below 1 Ω
      EFI MAIN1 relay terminal 3 - A33-1 (+B2) Always Below 1 Ω
      Standard Resistance (Check for short)
      Tester Connection Condition Specified Condition
      EFI MAIN1 relay terminal 1 or A35-13 (SSHUT) - Body ground Always 10 kΩ or higher
      EFI MAIN1 relay terminal 3, A34-6 (+B) or A33-1 (+B2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT TERMINAL VOLTAGE (EFI MAIN1 RELAY)


    1. A004IVCE01
      Text in Illustration
      *1 Engine Room Relay Block Assembly
      *2 EFI MAIN1 Relay Terminal

      Remove the EFI MAIN1 relay from the engine room relay block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      EFI MAIN1 relay terminal 2 - Body ground Always 11 to 14 V
      EFI MAIN1 relay terminal 5 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (IG2 RELAY - ECM)


    1. Remove the IG2 relay from the engine room relay block assembly.

    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
      IG2 relay terminal 3 - A33-27 (IGSW) Always Below 1 Ω
      IG2 relay terminal 1 - Body ground Always Below 1 Ω
      Standard Resistance (Check for short)
      Tester Connection Condition Specified Condition
      IG2 relay terminal 3 or A33-27 (IGSW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. INSPECT RELAY (IG2)


    1. Inspect the IG2 relay Click here.


    NG

    REPLACE RELAY (IG2)

    OK

  10. INSPECT TERMINAL VOLTAGE (IG2 RELAY)


    1. A004HO5E01
      Text in Illustration
      *1 Engine Room Relay Block Assembly
      *2 IG2 Relay Terminal

      Remove the IG2 relay from the engine room relay block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      IG2 relay terminal 5 - Body ground Always 11 to 14 V
      Result
      Result Proceed to
      NG A
      OK (w/ Entry and Start System) B
      OK (w/o Entry and Start System) C

    A

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    C

    CHECK HARNESS AND CONNECTOR (IG2 RELAY - IGNITION OR STARTER SWITCH ASSEMBLY) Click here

    B

  11. CHECK HARNESS AND CONNECTOR (IG2 RELAY - CERTIFICATION ECU)


    1. Remove the IG2 relay from the engine room relay block assembly.

    2. Disconnect the certification ECU connector.

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

      Standard Resistance (Check for open)
      Tester Connection Condition Specified Condition
      IG2 relay terminal 2 - D48-9 (IG2D) Always Below 1 Ω
      Standard Resistance (Check for short)
      Tester Connection Condition Specified Condition
      IG2 relay terminal 2 or D48-9 (IG2D) - Body ground Always 10 kΩ or higher

    OK

    GO TO ENTRY AND START SYSTEM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  12. CHECK HARNESS AND CONNECTOR (IG2 RELAY - IGNITION OR STARTER SWITCH ASSEMBLY)


    1. Remove the IG2 relay from the engine room relay block assembly.

    2. Disconnect the ignition or starter 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
      IG2 relay terminal 2 - D55-6 (IG2) Always Below 1 Ω
      Standard Resistance (Check for short)
      Tester Connection Condition Specified Condition
      IG2 relay terminal 2 or D55-6 (IG2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY


    1. Inspect the ignition or starter switch assembly Click here.


    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    NG

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY Click here