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 start ability. While the engine is being cranked, the battery positive voltage is applied to terminal STA of the ECM. The starter signal is mainly used to increase the fuel injection volume for the starting injection control and after-start injection control.

WIRING DIAGRAM

A01BGZ7E02

INSPECTION PROCEDURE

Tech Tips

This diagnostic chart is based on the premise that the engine is being cranked under normal conditions. If the engine does not crank, proceed to the problem symptoms table Click here.

PROCEDURE


  1. READ VALUE USING GTS (STARTER SIGNAL)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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

    5. Read the value.

      Result
      Ignition Switch Condition Starter Signal
      ON OFF
      START ON

    NG

    INSPECT IGNITION SWITCH Click here

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  2. INSPECT IGNITION SWITCH


    1. Inspect the ignition switch Click here.


    NG

    REPLACE IGNITION SWITCH

    OK

  3. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - ECM)


    1. Disconnect the ignition switch connector.

    2. Disconnect the ECM connector.

    3. Remove the ST relay from the instrument panel relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      H25-1 (ST1) - B74-33 (STA) Always Below 1 Ω
      H25-1 (ST1) or B74-33 (STA) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here