SFI SYSTEM Cranking Holding Function Circuit

DESCRIPTION

The cranking holding control system provides current to the starter when the ECM detects the engine switch start signal (STSW). When the ECM performs a firing judgment, the system cuts current to the starter. When an ECM receives the STSW signal, it turns on the ACC cut, which prevents flickering of the combination meter, clock, audio system, etc. Also, the ECM sends a signal to the ECM STAR terminal. Then the STAR output signal travels through the Park/Neutral Position (PNP) switch to the starter relay, causing the starter to activate.

When the engine is cranking, the starter operation signal is sent to the ECM STA terminal.

A0155K5E40

WIRING DIAGRAM

Refer to DTC P0617 Click here.

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK CRANKING


    1. Check the cranking of the engine.

      Result
      Result Proceed to
      Cranking possible and holding control operates A
      Does not crank B
      Cranking possible but holding control does not operate C

    B

    READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL) Click here

    C

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

    A

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  2. READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / Starter Signal.

    5. Check the value displayed on the tester when the engine switch is turned to the START.

      Standard
      Engine Switch Position Display (Starter Signal)
      On (IG) OFF
      START ON

    NG

    INSPECT STARTER CUT RELAY (ST CUT) Click here

    OK

  3. INSPECT STARTER RELAY (ST)


    1. Inspect the starter relay (ST) Click here.


    NG

    REPLACE STARTER RELAY

    OK

  4. CHECK HARNESS AND CONNECTOR (STARTER RELAY - PNP SWITCH)


    1. Remove the starter relay (ST) from the engine room relay block.

    2. Disconnect the C24 PNP switch.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      ST relay (2) - C24-5 Always Below 1 Ω
      ST relay (2) or C24-5 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK STARTER RELAY (POWER SOURCE)


    1. 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 (1) - ST relay (5) Always 11 to 14 V

    NG

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

    OK

  6. INSPECT STARTER


    1. Inspect the starter Click here.


    NG

    REPAIR OR REPLACE STARTER Click here

    OK

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

  7. INSPECT STARTER CUT RELAY (ST CUT)


    1. Inspect the starter cut relay (ST CUT) Click here.


    NG

    REPLACE STARTER CUT RELAY

    OK

  8. CHECK HARNESS AND CONNECTOR (ST CUT RELAY - PNP SWITCH, ECM)


    1. Remove the starter cut relay (ST CUT) from the engine room relay block.

    2. Disconnect the C24 PNP switch connector.

    3. Disconnect the C45 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      ST CUT relay (5) - C45-16 (STAR) Always Below 1 Ω
      ST CUT relay (3) - C24-4 Always Below 1 Ω
      ST CUT relay (5) or C45-16 (STAR) - Body ground Always 10 kΩ or higher
      ST CUT relay (3) or C24-4 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. INSPECT PARK/NEUTRAL POSITION SWITCH


    1. Inspect the park/neutral position switch Click here.


    NG

    REPLACE PARK/NEUTRAL POSITION SWITCH Click here

    OK

  10. CHECK HARNESS AND CONNECTOR (PNP SWITCH - ECM)


    1. Disconnect the C24 PNP switch connector.

    2. Disconnect the A38 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C24-5 - A38-46 (STA) Always Below 1 Ω
      C24-5 or A38-46 (STA) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      NG A
      OK B

    B

    REPLACE ECM Click here

    A

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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


    1. Disconnect the E4 main body ECU connector.

    2. Disconnect the A38 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E4-4 (STSW) - A38-14 (STSW) Always Below 1 Ω
      E4-4 (STSW) or A38-14 (STSW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. CHECK HARNESS AND CONNECTOR (STARTER CUT RELAY - PNP SWITCH, ECM)


    1. Remove the starter cut relay (ST CUT) from the engine room relay block.

    2. Disconnect the C24 PNP switch connector.

    3. Disconnect the C45 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      ST CUT relay (5) - C45-16 (STAR) Always Below 1 Ω
      ST CUT relay (3) - C24-4 Always Below 1 Ω
      ST CUT relay (5) or C45-16 (STAR) - Body ground Always 10 kΩ or higher
      ST CUT relay (3) or C24-4 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here

  13. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  14. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check the starter operation.

      OK
      Malfunction has been repaired successfully.

    NG

    GO TO ENTRY AND START SYSTEM (ENGINE DOES NOT START) Click here

    OK

    END