SFI 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

A01OAR6E01

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. INSPECT SEMICONDUCTOR PWR INTEGRATION ECU (POWER SOURCE)

    A01OAZCC04
    *a

    Front view of wire harness 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 PWR 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 PWR INTEGRATION ECU Click here

    OK

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


    1. Disconnect the semiconductor pwr integration ECU connector.

    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
      1G-6 - A72-46 (MREL) Always Below 1 Ω
      1G-8 - A72-2 (+B) Always Below 1 Ω
      1G-7 - A72-3 (+B2) Always Below 1 Ω
      1G-6 or A72-46 (MREL) - Body ground and other terminals Always 10 kΩ or higher
      1G-8 or A72-2 (+B) - Body ground and other terminals Always 10 kΩ or higher
      1G-7 or A72-3 (+B2) - Body ground and other terminals 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
      F6-16 (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. B004GC6C25
      *a

      Front view of wire harness 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
      A72-37 (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 (SEMICONDUCTOR PWR INTEGRATION ECU - ECM)


    1. Disconnect the semiconductor pwr integration ECU connector.

    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
      1F-4 - A72-37 (IGSW) Always Below 1 Ω
      1F-4 or A72-37 (IGSW) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - SEMICONDUCTOR PWR INTEGRATION ECU)


    1. Disconnect the certification 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
      A13-3 (IG1D) - 1E-1 Always Below 1 Ω
      A13-3 (IG1D) or 1E-1 - Body ground and other terminals 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