SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, the battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the EFI MAIN relay coil, closing the EFI MAIN relay contacts and supplying power to terminal +B and +B2 of the ECM.

WIRING DIAGRAM

A01VI7GE03

CAUTION / NOTICE / HINT

Note


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

  • Perform electronic throttle learning after replacing the ECM Click here.

PROCEDURE


  1. INSPECT NO. 1 INTEGRATION RELAY (POWER SOURCE)

    A01VG9ZE03
    Text in Illustration
    *a

    Front view of wire harness connector

    (to No. 1 integration relay)

    1. Remove the No. 1 integration relay from the engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1C-1 - Body ground Always 11 to 14 V

    NG

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

    OK

  2. INSPECT NO. 1 INTEGRATION RELAY (EFI MAIN RELAY AND IG2 RELAY)

    A01VE7HE03
    Text in Illustration
    *a

    Component without harness connected

    (No. 1 integration relay)

    1. Remove the No. 1 integration relay from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1C-1 - 1D-9 Battery voltage not applied 10 kΩ or higher
      Battery voltage applied to terminals 1D-17 and 1E-10 Below 1 Ω
      1C-1 - 1E-4 Battery voltage not applied 10 kΩ or higher
      Battery voltage applied to terminals 1D-7 and 1E-10 Below 1 Ω

    NG

    REPLACE NO. 1 INTEGRATION RELAY Click here

    OK

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


    1. Remove the No. 1 integration relay from the engine room relay block.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A71-35 (MREL) - 1D-7 Always Below 1 Ω
      A71-24 (+B) - 1E-4 Always Below 1 Ω
      A71-23 (+B2) - 1E-4 Always Below 1 Ω
      A71-35 (MREL) or 1D-7 - Body ground Always 10 kΩ or higher
      A71-24 (+B) or 1E-4 - Body ground Always 10 kΩ or higher
      A71-23 (+B2) or 1E-4 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. 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
      A71-1 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT ECM (IGSW TERMINAL VOLTAGE)

    A01VK9VE02
    Text in Illustration
    *a

    Front view of wire harness connector

    (to ECM)

    1. Disconnect the ECM connector.

    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
      A71-4 (IGSW) - A71-1 (E1) Ignition switch ON 11 to 14 V
      Result
      Result Proceed to
      Outside standard range A
      Within standard range B

    B

    REPLACE ECM Click here

    A

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


    1. Disconnect the ECM connector.

    2. Remove the No. 1 integration relay from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A71-4 (IGSW) - 1D-9 Always Below 1 Ω
      A71-4 (IGSW) or 1D-9 - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      Outside standard range A
      Within standard range (w/ Entry and Start System) B
      Within standard range (w/o Entry and Start System) C

    A

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    C

    CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - IGNITION SWITCH) Click here

    B

  7. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - CERTIFICATION ECU)


    1. Remove the No. 1 integration relay from the engine room relay block.

    2. Disconnect the certification ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1D-17- F65-9 (IG2D) Always Below 1 Ω
      1E-10 - Body ground Always Below 1 Ω
      F65-9 (IG2D) or 1D-17 - Body ground Always 10 kΩ or higher

    OK

    CHECK ENTRY AND START SYSTEM (for Start Function) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  8. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - IGNITION SWITCH)


    1. Remove the No. 1 integration relay from the engine room relay block.

    2. Disconnect the ignition switch connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1D-17 - F13-6 (IG2) Always Below 1 Ω
      1E-10 - Body ground Always Below 1 Ω
      F13-6 (IG2) or 1D-17 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. INSPECT IGNITION SWITCH ASSEMBLY


    1. Inspect the ignition switch assembly Click here.


    OK

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

    NG

    REPLACE IGNITION SWITCH ASSEMBLY Click here