SFI SYSTEM Starter Signal Circuit

DESCRIPTION

While the engine is being cranked, current flows from terminal ST1 of the ignition switch to the park/neutral position switch (for automatic transaxle) and also flows to terminal STA of the ECM (STA Signal).

WIRING DIAGRAM

A017D4BE02

INSPECTION PROCEDURE

Tech Tips

This chart is based on the premise that the engine can crank normally. If the engine cannot crank normally, proceed to the problem symptoms table Click here.

PROCEDURE


  1. 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 1 - Body ground Engine cranking 9 to 14 V

      Tech Tips

      The engine does not crank because the relay is not installed.

    3. Reinstall the ST relay.


    NG

    INSPECT IGNITION SWITCH ASSEMBLY Click here

    OK

  2. INSPECT ST RELAY


    1. A017B6EE02

      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

  3. 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.


    NG

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

    OK

  4. 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 Cranking 9 to 14 V

    3. Reinstall the ST relay.


    NG

    CHECK HARNESS AND CONNECTOR (ST RELAY - IGNITION SWITCH ASSEMBLY) Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (ST RELAY - STARTER)


    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
      Tester Connection Condition Specified Condition
      ST relay terminal 3 - B12-1 Always Below 1 Ω

    4. Reconnect the starter connector.

    5. Reinstall the ST relay.


    NG

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

    OK

    REPAIR OR REPLACE STARTER ASSEMBLY

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


    1. A017EUKE01

      Remove the ST relay from engine room relay block.

    2. Disconnect the ignition switch assembly 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 5 - D21-2 (ST2) Always Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      ST relay terminal 5 or D21-2 (ST2) - Body ground Always 10 kΩ or higher

    4. Reinstall the ST relay.

    5. Reconnect the ignition switch assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ST RELAY - IGNITION SWITCH ASSEMBLY)

    OK

  7. INSPECT IGNITION SWITCH ASSEMBLY


    1. A017C4IE11

      Disconnect the ignition switch assembly connector.

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

      Standard resistance
      Tester Connection Ignition Switch Position Specified Condition
      All terminals LOCK 10 kΩ or higher
      D21-4 (AM1) - D21-3 (ST1) START Below 1 Ω

    3. Reconnect the ignition switch assembly connector.


    NG

    REPLACE IGNITION SWITCH ASSEMBLY Click here

    OK

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


    1. A017DORE01

      Remove the ST relay from the engine relay block.

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

    4. Reinstall the ST relay.

    5. Reconnect the park/neutral position switch connector.


    NG

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

    OK

  9. INSPECT PARK/NEUTRAL POSITION SWITCH


    1. Inspect the park/neutral position switch (U151E: Click here, U151F: Click here.

      Result:
      Result Proceed To
      OK A
      NG (with U151E) B
      NG (with U151F) C

    B

    REPLACE PARK/NEUTRAL POSITION SWITCH Click here

    C

    REPLACE PARK/NEUTRAL POSITION SWITCH Click here

    A

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


    1. A017G6DE03

      Disconnect the park/neutral position switch connector.

    2. Disconnect the ignition switch assembly connector.

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

      Standard resistance (Check for open)
      Tester Connection Condition Specified Condition
      B5-4 - D21-3 (ST1) Always Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      B5-4 or D21-3 (ST1) - Body ground Always 10 kΩ or higher

    4. Reconnect the park/neutral position switch connector.

    5. Reconnect the ignition switch assembly connector.


    NG

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

    OK

  11. INSPECT IGNITION SWITCH ASSEMBLY


    1. A017C4IE11

      Disconnect the ignition switch assembly connector.

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

      Standard resistance
      Tester Connection Ignition Switch Position Specified Condition
      All terminals LOCK 10 kΩ or higher
      D21-4 (AM1) - D21-3 (ST1) START Below 1 Ω

    3. Reconnect the ignition switch assembly connector.


    NG

    REPLACE IGNITION SWITCH ASSEMBLY Click here

    OK

  12. INSPECT FUSE (AM1 FUSE)


    1. A017CXCE02

      Remove the AM1 fuse from the instrument panel junction block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      AM1 fuse Always Below 1 Ω

    3. Reinstall the AM1 fuse.


    NG

    REPLACE FUSE (AM1 FUSE)

    OK

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