SFI SYSTEM(w/o EGR System) ECM Power Source Circuit

DESCRIPTION

When the power switch is turned on (IG), auxiliary battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes current to flow to the coil of the semiconductor pwr integration ECU (EFI MAIN relay), closing the contact and supplying power to terminals +B and +B2 of the ECM.

WIRING DIAGRAM

B003YC1E03

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. INSPECT SEMICONDUCTOR POWER INTEGRATION ECU (POWER SOURCE)

    B003Y8VC04
    *a

    Front view of wire harness or connector

    (to Semiconductor Pwr Integration ECU)

    1. Disconnect the semiconductor pwr integration ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1B-1 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - SEMICONDUCTOR PWR INTEGRATION ECU)

    OK

  2. CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - BODY GROUND)


    1. Disconnect the semiconductor pwr integration ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1D-14 - Body ground Always Below 1 Ω
      1G-5 - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT SEMICONDUCTOR POWER INTEGRATION ECU (EFI MAIN, IG2 RELAY)


    1. Inspect the semiconductor pwr integration ECU (EFI MAIN, IG2 relay).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SEMICONDUCTOR POWER INTEGRATION ECU Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (ECM - SEMICONDUCTOR PWR INTEGRATION ECU)


    1. Disconnect the ECM connector.

    2. Disconnect the semiconductor pwr integration ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A78-46 (MREL) - 1G-6 Always Below 1 Ω
      A78-2 (+B) - 1G-8 Always Below 1 Ω
      A78-3 (+B2) - 1G-7 Always Below 1 Ω
      A78-46 (MREL) or 1G-6 - Body ground Always 10 kΩ or higher
      A78-2 (+B) or 1G-8 - Body ground Always 10 kΩ or higher
      A78-3 (+B2) or 1G-7 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. 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
      F5-16 (E1) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK TERMINAL VOLTAGE (IGSW VOLTAGE)


    1. B003YD3C46
      *a

      Front view of wire harness or connector

      (to ECM)

      Disconnect the ECM connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A78-37 (IGSW) - Body ground Power switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

  7. CHECK HARNESS AND CONNECTOR (ECM - SEMICONDUCTOR PWR INTEGRATION ECU)


    1. Disconnect the ECM connector.

    2. Disconnect the semiconductor pwr integration ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A78-37 (IGSW) - 1F-4 Always Below 1 Ω
      A78-37 (IGSW) or 1F-4 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - SEMICONDUCTOR PWR INTEGRATION ECU)


    1. Disconnect the power management control ECU connector.

    2. Disconnect the semiconductor pwr integration ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K33-2 (IG1D) - 1E-1 Always Below 1 Ω
      K33-2 (IG1D) or 1E-1 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    GO TO ENTRY AND START SYSTEM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR