SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, the battery voltage is applied to the IGSW and BATT terminals 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 +B1 of the ECM.

WIRING DIAGRAM

A01VIZOE02

CAUTION / NOTICE / HINT

Note


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

  • Perform idle learning after replacing the ECM Click here.

PROCEDURE


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

    A01VG9ZE04
    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

    CHECK BATTERY TERMINAL Click here

    OK

  2. INSPECT NO. 1 INTEGRATION RELAY

    A01VE7HE04
    Text in Illustration
    *a

    Component without harness connected

    (to 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
      1C-1 - 1E-9 Always 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 A93 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A93-9 (MREL) - 1D-7 Always Below 1 Ω
      A93-2 (+B) - 1E-4 Always Below 1 Ω
      A93-1 (+B1) - 1E-4 Always Below 1 Ω
      A93-9 (MREL) or 1D-7 - Body ground Always 10 kΩ or higher
      A93-2 (+B) or 1E-4 - Body ground Always 10 kΩ or higher
      A93-1 (+B1) 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 A93 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A93-4 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. 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 A93 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1E-9 - A93-15 (BATT) Always Below 1 Ω
      1E-9 or A93-15 (BATT) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT ECM (IGSW TERMINAL VOLTAGE)

    A01VEXOE02
    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
      A93-37 (IGSW) - A93-4 (E1) Ignition switch ON 11 to 14 V
      Result
      Result Proceed to
      NG A
      OK B

    B

    REPLACE ECM Click here

    A

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


    1. Disconnect the A93 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
      A93-37 (IGSW) - 1D-9 Always Below 1 Ω
      A93-37 (IGSW) or 1D-9 - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (w/ Entry and Start System) A
      OK (w/o Entry and Start System) B
      NG C

    B

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

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

  8. 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 F65 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

  9. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - IGNITION OR STARTER SWITCH ASSEMBLY)


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

    2. Disconnect the F13 ignition or starter switch assembly 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

  10. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY


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


    OK

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

    NG

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY Click here

  11. CHECK BATTERY TERMINAL


    1. Check that the battery terminals are not loose or corroded Click here.

      OK
      Battery terminals are not loose or corroded.

    NG

    REPAIR OR REPLACE BATTERY TERMINAL

    OK

  12. INSPECT BATTERY


    1. Check that the battery is not depleted.

      OK
      Battery is not depleted.

    OK

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

    NG

    REPLACE BATTERY