ECD SYSTEM Starter Signal Circuit

DESCRIPTION

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

WIRING DIAGRAM

Refer to DTC P0617 Click here.

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following 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 Problem Symptoms Table Click here.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER


    1. Replace the normal DLC3 cable (12 V specification) for the intelligent tester with the 24 V DLC3 cable.

      Note

      Be sure to use the 24 V DLC3 cable when connecting the intelligent tester to the DLC3. Using the normal DLC3 cable (12 V specification) will cause damage to the tester.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the tester on.

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

    6. Read the value.

      OK
      Ignition Switch Condition ON START
      Starter Signal OFF ON

    NG

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

    OK

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

  2. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - ECM)


    1. Disconnect the ignition switch assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      I25-4 (ST1) - E39-6 (STA) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      I25-4 (ST1) or E39-6 (STA) - Body ground Always 10 kΩ or higher

    4. Reconnect the ignition switch assembly connector.

    5. Reconnect the ECM connector.


    NG

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

    OK

    REPLACE ECM Click here