SFI SYSTEM Starter Signal Circuit

DESCRIPTION

While the engine is being cranked, the ECM detects the starter drive signal (STA2 signal) from the engine stop and start ECU as the starter operation signal (STA signal) to perform engine control when the engine is started. When the start signal is input from the engine switch, the certification ECU (smart key ECU assembly) sends the operation signal (STAR signal) to the ST relay (starter pinion drive relay) via the park/neutral position switch assembly. Afterward, the starter drive signal (STA2) is sent to the ST NO. 2 relay by the delay circuit in the engine stop and start ECU, and the starter is driven until the signal that the engine completely started (NE signal) is detected.

WIRING DIAGRAM

Refer to DTC P0617.

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CAUTION / NOTICE / HINT

Note


  • After turning engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

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

PROCEDURE


  1. CHECK WHETHER ENGINE CAN BE CRANKED


    1. Check if the engine can be cranked.

      Result
      Result Proceed to
      Engine cannot be cranked A
      Engine can be cranked B

    B

    READ VALUE USING GTS (STARTER SIGNAL) Click here

    A

  2. READ VALUE USING GTS (STARTER SIGNAL)


    1. Connect the GTS to DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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


      Powertrain > Engine and ECT > Data List
      Tester Display
      Starter Signal

    5. Check the result when the engine switch is on (IG) and the engine starts.

      OK
      Condition Starter Signal
      Engine switch on (IG) OFF
      Engine started ON
      Result
      Proceed to
      OK
      NG

    OK

    CHECK SMART ENTRY AND START SYSTEM Click here

    NG

  3. CHECK HARNESS AND CONNECTOR (ECM - ENGINE STOP AND START ECU - ST NO. 2 RELAY)


    1. Disconnect the ECM connector.

    2. Disconnect the engine stop and start ECM connector.

    3. Remove the ST NO. 2 relay from the No. 2 engine room relay block and junction block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A35-29 (STA) - A38-23 (STA2) Always Below 1 Ω
      A35-29 (STA) - 2 (ST NO. 2 relay terminal holder) Always Below 1 Ω
      A38-23 (STA2) - 2 (ST NO. 2 relay terminal holder) Always Below 1 Ω
      A35-29 (STA) or A38-23 (STA2) - Body ground and other terminals Always 10 kΩ or higher
      A35-29 (STA) or 2 (ST NO. 2 relay terminal holder) - Body ground and other terminals Always 10 kΩ or higher
      A38-23 (STA2) or 2 (ST NO. 2 relay terminal holder) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (ECM - ENGINE STOP AND START ECU - PARK/NEUTRAL POSITION SWITCH - CERTIFICATION ECU)


    1. Disconnect the ECM connector.

    2. Disconnect the engine stop and start ECM connector.

    3. Disconnect the park/neutral position switch assembly connector.

    4. Disconnect the certification ECU (smart key ECU assembly) connector

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A35-23 (NSW) - A38-28 (CLL) Always Below 1 Ω
      I51-10 (STAR) - C14-4 (B) Always Below 1 Ω
      A35-23 (NSW) - I51-10 (STAR) Always Below 1 Ω
      A38-28 (CLL) - I51-10 (STAR) Always Below 1 Ω
      A35-23 (NSW) - C14-4 (B) Always Below 1 Ω
      A38-28 (CLL) - C14-4 (B) Always Below 1 Ω
      A35-23 (NSW) or A38-28 (CLL) - Body ground and other terminals Always 10 kΩ or higher
      I51-10 (STAR) or C14-4 (B) - Body ground and other terminals Always 10 kΩ or higher
      A35-23 (NSW) or I51-10 (STAR) - Body ground and other terminals Always 10 kΩ or higher
      A38-28 (CLL) or I51-10 (STAR) - Body ground and other terminals Always 10 kΩ or higher
      A35-23 (NSW) or C14-4 (B) - Body ground and other terminals Always 10 kΩ or higher
      A38-28 (CLL) or C14-4 (B) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. READ VALUE USING GTS (STARTER SIGNAL)


    1. Connect the GTS to DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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


      Powertrain > Engine and ECT > Data List
      Tester Display
      Starter Signal

    5. Check the result when the engine switch is on (IG) and the engine starts.

      OK
      Condition Starter Signal
      Engine switch on (IG) OFF
      Engine started ON
      Result
      Proceed to
      OK
      NG

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ST RELAY - ECM)