СИСТЕМА ECD Starter Signal Circuit

DESCRIPTION

When the engine is cranked, the intake air flow becomes slow, so fuel vaporization is poor. A rich mixture is therefore necessary in order to achieve good startability. While the engine is being cranked, the battery voltage is applied to terminal STA of the ECM. The starter signal is mainly used to increase the fuel injection volume for starting and after-start injection control.

WIRING DIAGRAM

A01DV8SE02

INSPECTION PROCEDURE

When using intelligent tester:

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (STA SIGNAL)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch ON and turn the intelligent tester ON.

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

    4. Read the STA signal on the intelligent tester while the starter operates.

      Result
      Ignition Switch Position STA Signal
      LOCK, ACC, ON OFF
      STA ON

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

    NG

  2. INSPECT FUSE (ST)


    1. A01DXFQE01

      Remove the ST fuse from the instrument panel junction block.

    2. Measure the resistance of the fuse.

      Standard resistance
      Tester Connection Specified Condition
      ST fuse Below 1 Ω

    NG

    CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE, AND REPLACE FUSE

    OK

  3. CHECK WIRE HARNESS (IGNITION SWITCH - ST FUSE, ST FUSE - ECM)


    1. A01DXRKE01

      Check the wire harness between the ignition switch and ST fuse.


      1. Disconnect the ignition switch connector.

      2. Remove the ST fuse from the instrument panel junction block.

      3. Measure the resistance of the wire harness side connectors.

        Standard resistance
        Tester Connection Specified Condition
        I6-7 (ST2) - Instrument panel junction block ST fuse terminal 1 Below 1 Ω
        I6-7 (ST2) or Instrument panel junction block ST fuse terminal 1 - Body ground 10 kΩ or higher
    2. A01DYPZE01

      Check the wire harness between the ST fuse and ECM.


      1. Remove the ST fuse from the instrument panel junction block.

      2. Disconnect the E20 ECM connector.

      3. Measure the resistance of the wire harness side connectors.

        Standard resistance
        Tester Connection Specified Condition
        Instrument panel junction block ST fuse terminal 2 - E20-11 (STA) Below 1 Ω
        Instrument panel junction block ST fuse terminal 2 or E20-11 (STA) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE ECM

When not using intelligent tester:

PROCEDURE


  1. CHECK ECM (STA VOLTAGE)

    A01E2VTE39

    1. Turn the ignition switch ON.

    2. Measure the voltage of the ECM connector.

      Standard voltage
      Tester Connection Condition Specified Condition
      E20-11 (STA) - E23-14 (E1) Cranking 6 V or more

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

    NG

  2. INSPECT FUSE (ST)


    1. A01DXFQE01

      Remove the ST fuse from the instrument panel junction block.

    2. Measure the resistance of the ST fuse.

      Standard resistance
      Tester Connection Specified Condition
      ST fuse Below 1 Ω

    NG

    CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE, AND REPLACE FUSE

    OK

  3. CHECK WIRE HARNESS (IGNITION SWITCH - ST FUSE, ST FUSE - ECM)


    1. A01DXRKE01

      Check the wire harness between the ignition switch and ST fuse.


      1. Disconnect the ignition switch connector.

      2. Remove the ST fuse from the instrument panel junction block.

      3. Measure the resistance of the wire harness side connectors.

        Standard resistance
        Tester Connection Specified Condition
        I6-7 (ST2) - Instrument panel junction block ST fuse terminal 1 Below 1 Ω
        I6-7 (ST2) or Instrument panel junction block ST fuse terminal 1 - Body ground 10 kΩ or higher
    2. A01DYPZE01

      Check the wire harness between the ST fuse and ECM.


      1. Remove the ST fuse from the instrument panel junction block.

      2. Disconnect the E20 ECM connector.

      3. Measure the resistance of the wire harness side connectors.

        Standard resistance
        Tester Connection Specified Condition
        Instrument panel junction block ST fuse terminal 2 - E20-11 (STA) Below 1 Ω
        Instrument panel junction block ST fuse terminal 2 or E20-11 (STA) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE ECM