SFI SYSTEM Starter Signal Circuit

DESCRIPTION

While the engine is being cranked, current flows from terminal ST1 of the ignition switch to the clutch start switch assembly or the park/neutral position switch assembly and also flows to terminals STA of the ECM (STA signal).

WIRING DIAGRAM

A01194BE01

INSPECTION PROCEDURE

Note


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

  • After turning ignition 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 Click here.

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 INTELLIGENT TESTER (STARTER SIGNAL) Click here

    A

  2. READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

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

    5. Check the result when the ignition switch is turned ON and the engine starts.

      OK
      Ignition Switch Position Starter Signal
      Ignition switch ON OFF
      Engine start ON

    NG

    READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL) Click here

    OK

  3. INSPECT IGNITION SWITCH ASSEMBLY


    1. Inspect the ignition switch assembly Click here.


    NG

    REPLACE IGNITION SWITCH ASSEMBLY Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - ST RELAY - STARTER)


    1. Remove the ST relay from the No. 1 engine room relay block.

    2. Disconnect the D28 ignition switch assembly connector.

    3. Disconnect the B32 starter connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D28-8 (ST2) - 5 (ST relay) Always Below 1 Ω
      3 (ST relay) - B32-1 (Starter) Always Below 1 Ω
      D28-8 (ST2) or 5 (ST relay) - Body ground Always 10 kΩ or higher
      3 (ST relay) or B32-1 (Starter) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Remove the ST relay from the No. 1 engine room relay block.

    2. Disconnect the A18 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A18-48 (STA) - 2 (ST relay) Always Below 1 Ω
      1 (ST relay) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT BATTERY


    1. Check that the battery is not depleted Click here.

      OK
      Battery is not depleted.

    NG

    CHARGE OR REPLACE BATTERY

    OK

  7. CHECK BATTERY TERMINAL


    1. Check that the battery terminals are not loose or corroded.

      OK
      Battery terminals are not loose or corroded.

    NG

    REPAIR OR REPLACE BATTERY TERMINAL

    OK

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

  8. READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)


    1. Disconnect the D37 power management control ECU connector.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the tester on.

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

    5. Check the result when the ignition switch is turned ON and the engine starts.

      OK
      Ignition Switch Position Starter Signal
      Ignition switch ON OFF
      Engine start ON
      Result
      Result Proceed to
      NG A
      OK B

    B

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    A

  9. INSPECT IGNITION SWITCH ASSEMBLY


    1. Inspect the ignition switch assembly Click here.

      Result
      Result Proceed to
      OK (for CVT) A
      OK (for Manual Transaxle) B
      NG C

    B

    INSPECT CLUTCH START SWITCH ASSEMBLY Click here

    C

    REPLACE IGNITION SWITCH ASSEMBLY Click here

    A

  10. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY


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


    NG

    REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY Click here

    OK

  11. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM)


    1. Disconnect the D28 ignition switch assembly connector.

    2. Disconnect the B13 park/neutral position switch assembly connector.

    3. Disconnect the A18 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D28-1 (ST1) - B13-4 (B) Always Below 1 Ω
      B13-4 (B) - A18-25 (NSW) Always Below 1 Ω
      D28-1 (ST1), B13-4 (B) or A18-25 (NSW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Remove the ST relay from the No. 1 engine room relay block.

    2. Disconnect the A18 ECM connector.

    3. Disconnect the B13 park/neutral position switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B13-5 (L) - A18-48 (STA) Always Below 1 Ω
      A18-48 (STA) - 2 (ST relay) Always Below 1 Ω
      1 (ST relay) - Body ground Always Below 1 Ω
      B13-5 (L) or A18-48 (STA) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

  13. INSPECT CLUTCH START SWITCH ASSEMBLY


    1. Inspect the clutch start switch assembly Click here.


    NG

    REPLACE CLUTCH START SWITCH ASSEMBLY Click here

    OK

  14. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - CLUTCH START SWITCH ASSEMBLY - ECM)


    1. Disconnect the D28 ignition switch assembly connector.

    2. Disconnect the A29 clutch start switch assembly connector.

    3. Disconnect the A18 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D28-1 (ST1) - A29-2 Always Below 1 Ω
      A29-2 - A18-25 (NSW) Always Below 1 Ω
      D28-1 (ST1), A29-2 or A18-25 (NSW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  15. CHECK HARNESS AND CONNECTOR (ST RELAY - ECM - CLUTCH START SWITCH ASSEMBLY)


    1. Remove the ST relay from the No. 1 engine room relay block.

    2. Disconnect the A18 ECM connector.

    3. Disconnect the A29 clutch start switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A29-1 - A18-48 (STA) Always Below 1 Ω
      A18-48 (STA) - 2 (ST Relay) Always Below 1 Ω
      1 (ST Relay) - Body ground Always Below 1 Ω
      A29-1 or A18-48 (STA) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

  16. READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

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

    5. Check the result when the ignition switch is turned ON and engine starts.

      OK
      Ignition Switch Position Starter Signal
      Ignition switch ON OFF
      Engine start ON

    NG

    CHECK HARNESS AND CONNECTOR (ECM - ST RELAY) Click here

    OK

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

  17. CHECK HARNESS AND CONNECTOR (ECM - ST RELAY)


    1. Remove the ST relay from the No. 1 engine room relay block.

    2. Disconnect the A18 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A18-48 (STA) - 2 (ST relay) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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