STOP AND START SYSTEM Starter Inrush Current Reduction Relay Circuit

DESCRIPTION

The starter inrush current reduction relay reduces the drop in battery voltage when the starter is operated.

When battery voltage drops below the minimum threshold, stop and start control is prohibited. To avoid this, the stop and start ECU activates the start inrush current reduction relay approximately 0.1 seconds after ST/ST2 relay turns on, so that current flows through the resistor, lowering the current flowing to the starter motor and reducing the drop in battery voltage.

A005HJVE11

WIRING DIAGRAM

Refer to P0617 Click here.

PROCEDURE


  1. INSPECT BATTERY


    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 / Stop and Start / Active Test / Starter Motor Drive Magnet Switch / Min Volt (After Cranking)

    5. Connect the oscilloscope positive probe to the positive (+) terminal on the battery, and the negative probe to the negative (-) terminal on the battery.

    6. Read the number of drops in the waveform when the starter motor is forced to operate in the Active Test and the minimum voltage value after cranking in the Data Monitor.

      Note


      • Starter motor operation during the Active Test stops automatically in 3 seconds.

      • Do not force the starter pinion to operate.

      A005GIIE03
      OK
      There are 2 peaks in the voltage waveform, and minimum voltage after cranking is approximately 7.6 V or more
      Result
      [Number of drops in waveform] Result Minimum voltage after cranking (Data Monitor item) Proceed to
      There are 2 drops. 7.6 V or more A
      There are 2 drops. 7.6 V or less B
      There are not 2 drops. 7.6 V or more C
      There are not 2 drops. 7.6 V or less D

    B

    INSPECT BATTERY Click here

    C

    REPLACE STARTER INRUSH CURRENT REDUCTION RELAY Click here

    D

    REPLACE STARTER INRUSH CURRENT REDUCTION RELAY AND INSPECT BATTERY

    A

  2. INSPECT ENGINE STOP AND START ECU


    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 / Stop and Start / Active Test / Starter Motor Drive Magnet Switch

    5. Connect the oscilloscope positive probe to the positive (+) terminal on the battery and the A73-21 (STA) terminal on the engine stop and start ECU, and then connect the negative probe to the negative (-) terminal on the battery and the A72-8 (GND) terminal on the engine stop and start ECU.

      A005GNIE02
      Text In Illustration
      *a

      Component with harness connected:

      (Engine Stop and Start ECU)

      		 - -

    6. Read the battery voltage when the starter motor is forced to operate in the Active Test

      Note

      Starter operation in the Active Test stops automatically in 3 seconds.

      A005KFGE14
      OK
      The minimum voltage immediately after cranking is at least 7.6 V, and approximately 8.2 V or more approximately 0.05 seconds after the ST relay is turned on.

      Tech Tips

      Check the following items at the same time using the GTS.


      • Powertrain / Stop and Start / Data List / Min Volt (After Cranking) : 7.6 V or more

      • Powertrain / Stop and Start / Data List / Min Voltage (Cranking) : 7.6 V or more


    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    INSPECT BATTERY Click here