SFI SYSTEM Cranking Holding Function Circuit

DESCRIPTION

The system detects the ignition switch's starting signal (STSW) and then supplies current to the starter until the ECM judges that the engine has started successfully. The purpose is to reduce the holding time of the ignition key.

A017ER1E02

WIRING DIAGRAM

A017FOHE02

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK CRANKING


    1. When starting the engine, check whether the starter motor starts.

      OK
      Engine is cranking.

    NG

    READ VALUE USING INTELLIGENT TESTER (STA SIGNAL) Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

  2. READ VALUE USING INTELLIGENT TESTER (STA SIGNAL)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG).

    3. Turn the tester on.

    4. Select the following menu items: Powertrain / Engine and ECT / Data List / Starter Signal.

    5. Check the result when the ignition switch is turned on (IG) and when the engine is started.

      OK
      Display (Starter Signal) Condition
      OFF Ignition switch on (IG)
      ON Engine start

    NG

    CHECK ECM (STAR AND STSW VOLTAGE) Click here

    OK

  3. INSPECT ST RELAY


    1. A017B6E

      Remove the ST 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
      3 - 5 When no battery voltage applied terminals 1 and 2 10 kΩ or higher
      3 - 5 When battery voltage applied terminals 1 and 2 Below 1 Ω

    3. Reinstall the ST relay.


    NG

    REPLACE ST RELAY

    OK

  4. CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH - ST RELAY)


    1. A017CCFE01

      Disconnect the park/neutral position switch connector.

    2. Remove the ST relay from the engine room relay block.

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

      Standard resistance (check for open)
      Tester Connection Condition Specified Condition
      B5-5 - ST relay terminal (2) Always Below 1 Ω
      Standard resistance (check for short)
      Tester Connection Condition Specified Condition
      B5-5 or ST relay terminal (2) - Body ground Always 10 kΩ or higher

    4. Reconnect the park/neutral position switch connector.

    5. Reinstall the ST relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (PARK/NEUTRAL POSITION SWITCH - ST RELAY)

    OK

  5. CHECK HARNESS AND CONNECTOR (ST RELAY - BODY GROUND)


    1. A017EV2E01

      Remove the ST 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
      ST relay terminal (2) - Body ground Always Below 1 Ω

    3. Reinstall the ST relay to the engine room relay block.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ST RELAY - BODY GROUND)

    OK

  6. INSPECT TERMINAL VOLTAGE (ST RELAY TERMINAL)


    1. A017EV2E01

      Remove the ST 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
      ST relay terminal (5) - Body ground Always 9 to 14 V

    3. Reinstall the ST relay to the engine room relay block.


    NG

    INSPECT FUSIBLE LINK (ST FUSE) Click here

    OK

  7. INSPECT STARTER ASSEMBLY


    1. Inspect the starter assembly Click here.


    NG

    REPLACE STARTER ASSEMBLY Click here

    OK

  8. CHECK HARNESS AND CONNECTOR (ST RELAY - STARTER ASSEMBLY)


    1. A017CIGE01

      Remove the ST relay from the engine room relay block.

    2. Disconnect the starter connector.

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

      Standard resistance (check for open)
      Tester Connection Condition Specified Condition
      ST relay terminal (3) - B12-1 Always Below 1 Ω
      Standard resistance (check for short)
      Tester Connection Condition Specified Condition
      ST relay terminal (3) or B12-1 - Body ground Always 10 kΩ or higher

    4. Reconnect the starter connector.

    5. Reinstall the ST relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ST RELAY - STARTER ASSEMBLY)

    OK

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

  9. INSPECT FUSIBLE LINK (ST FUSE)


    1. A017ENJE09

      Remove the fusible link 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
      Fusible link Always Below 1 Ω

    3. Reinstall the fusible link.


    NG

    REPLACE FUSIBLE LINK

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - STARTER RELAY)

  10. CHECK ECM (STAR AND STSW VOLTAGE)


    1. A017BQGE23

      Start the engine.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      B3-12 (STSW) - Body ground Cranking 9 to 14 V
      Result
      Terminal STAR Terminal STSW Proceed to
      9 to 14 V 9 to 14 V A
      0 V 9 to 14 V B
      0 V 0 V C

    B

    REPLACE ECM Click here

    C

    CHECK HARNESS AND CONNECTOR (ECM - MAIN BODY ECU) Click here

    A

  11. INSPECT PARK/NEUTRAL POSITION SWITCH


    1. A017D91E01

      Disconnect the park/neutral position switch connector.

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

      Standard resistance
      Shift Position Tester Connection Specified Condition
      P 2 - 6, 4 - 5 Below 1 Ω
      R 1 - 2 Below 1 Ω
      N 2 - 9, 4 - 5 Below 1 Ω
      D 2 - 7 Below 1 Ω
      2 2 - 3 Below 1 Ω
      L 2 - 8 Below 1 Ω
      Result:
      Result Proceed To
      OK A
      NG (with U151E)) B
      NG (with U151F) C

    3. Reconnect the park/neutral position switch connector.


    B

    REPLACE PARK/NEUTRAL POSITION SWITCH Click here

    C

    REPLACE PARK/NEUTRAL POSITION SWITCH Click here

    A

  12. CHECK HARNESS AND CONNECTOR (ECM - PARK/NEUTRAL POSITION SWITCH)


    1. A017EDTE01

      Disconnect the ECM connector.

    2. Disconnect the park/neutral position switch connector.

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

      Standard resistance (check for open)
      Tester Connection Condition Specified Condition
      B3-11 (STA) - B5-5 Always Below 1 Ω
      Standard resistance (check for short)
      Tester Connection Condition Specified Condition
      B3-11 (STA) or B5-5 - Body ground Always 10 kΩ or higher

    4. Reconnect the ECM connector.

    5. Reconnect the park/neutral position switch connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - PARK/NEUTRAL POSITION SWITCH)

    OK

  13. INSPECT RELAY (ST CUT RELAY)


    1. A017B6E

      Remove the ST CUT 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
      3 - 5 When no battery voltage applied terminals 1 and 2 10 kΩ or higher
      3 - 5 When battery voltage applied terminals 1 and 2 Below 1 Ω

    3. Reinstall the ST CUT relay.


    NG

    REPLACE RELAY

    OK

  14. INSPECT TERMINAL VOLTAGE (ST CUT RELAY TERMINAL)


    1. A017CQ3E01

      Remove the ST CUT relay from the engine room relay block.

    2. Turn the ignition switch on (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      2 - Body ground Ignition switch on (IG) 9 to 14 V

    4. Reinstall the ST CUT relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ST CUT RELAY - IG2 RELAY)

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ST CUT RELAY - BODY GROUND)

  15. CHECK HARNESS AND CONNECTOR (ECM - MAIN BODY ECU)


    1. A017FC3E01

      Disconnect the ECM connector.

    2. Disconnect the main body 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
      B3-12 (STSW) - D9-4 (STSW) Always Below 1 Ω
      Standard resistance (check for short)
      Tester Connection Condition Specified Condition
      B3-12 (STSW) or D9-4 (STSW) - Body ground Always 10 kΩ or higher

    4. Reconnect the ECM connector.

    5. Reconnect the main body ECU connector.


    NG

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

    OK

    CHECK SMART ENTRY AND START SYSTEM Click here