STOP AND START SYSTEM(for 3ZR-FAE) Starter Inrush Current Reduction Relay Circuit

DTC Code DTC Name
Starter Inrush Current Reduction Relay Circuit

DESCRIPTION

The starter inrush current reduction relay prevents the battery voltage from becoming dropping excessively while the starter assembly is operating. If the battery voltage drops below the threshold, stop and start control will be prohibited. In order to prevent this, the engine stop and start ECU operates the starter inrush current reduction relay for approximately 0.1 seconds after the ST NO. 2 relay is activated. By allowing current to flow to the starter inrush current reduction relay, the current that flows to the starter motor is reduced, preventing the battery voltage from dropping excessively.

A285269E08

WIRING DIAGRAM

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CAUTION / NOTICE / HINT

Tip:

  • Starter inrush current reduction relay stuck on:

    When the engine is started by stop and start control, a large amount of current will flow to the starter assembly, the battery voltage will drop excessively and stop and start control will be canceled.

  • Starter inrush current reduction relay stuck off:

    Operating current will always flow through the starter inrush current reduction relay and the cranking speed will be low.

PROCEDURE

  1. CHECK WAVEFORM (STARTER INRUSH CURRENT REDUCTION RELAY)

    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 / Data List / Min Volt(After Cranking).

    5. Select the Data List item "Min Volt(After Cranking)".

      Powertrain > Stop and Start > Active Test

      Active Test Display

      Starter Motor Drive Magnet Switch

      Data List Display

      Min Volt(After Cranking)

    6. Connect the positive (+) lead of an oscilloscope to the positive (+) battery terminal and the negative (-) lead to the negative (-) battery terminal.

    7. While performing the Active Test "Starter Motor Drive Magnet Switch" to forcibly operate the starter motor, count the number of times the waveform drops and check the Data List item "Min Volt(After Cranking)".

      Note:

      • The Active Test "Starter Motor Drive Magnet Switch" is stopped automatically after the starter motor operates for 3 seconds.

      • Do not forcibly operate the starter pinion.

      A285238E02

      Standard

      Specified battery

      The voltage waveform has 2 peaks and the "Min Volt (After Cranking)" Data List item (the minimum voltage after the starter begins operation) is 7.66 V or higher

      Non-specified battery

      The voltage waveform has 2 peaks and the "Min Volt (After Cranking)" Data List item (the minimum voltage after the starter begins operation) is 8.92 V or higher

      Result

      Number of Times Waveform Dropped

      Min Volt(After Cranking) (Data List Item)

      Proceed to

      2 times

      7.66 V or higher*1, 8.92 V or higher*2

      A

      2 times

      Below 7.66 V*1, Below 8.92 V*2

      B

      Less than 2 times

      7.66 V or higher*1, 8.92 V or higher*2

      C

      Less than 2 times

      Below 7.66 V*1, Below 8.92 V*2

      D

      • *1: Specified battery

      • *2: Non-specified battery

    B

    CHECK BATTERY

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    C

    REPLACE STARTER INRUSH CURRENT REDUCTION RELAY

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    D

    REPLACE AND CHECK BATTERY

    A

  2. CHECK WAVEFORM (BATTERY VOLTAGE WHEN STARTER ASSEMBLY OPERATED)

    1. Enter the following menus: Powertrain / Stop and Start / Active Test / Starter Motor Drive Magnet Switch.

    2. Connect the positive (+) lead of an oscilloscope to the positive (+) battery terminal and the negative (-) lead to the negative (-) battery terminal. Also connect the oscilloscope to terminals A66-21 (STA) and A65-8 (GND) of the stop and start ECU.

      A350366C12

      *a

      Component with harness connected

      (Engine Stop and Start ECU)

      -

      -

    3. While performing the Active Test "Starter Motor Drive Magnet Switch" to forcibly operate the starter motor, measure the battery voltage.

      Note:

      The Active Test "Starter Motor Drive Magnet Switch" is stopped automatically after the starter motor operates for 3 seconds.

      A287573E10

      Standard

      Specified battery

      The minimum voltage immediately after cranking is 7.66 V or higher and the voltage approximately 0.03 seconds after the ST NO. 1 relay is turned ON is approximately 7.65 V or higher

      Non-specified battery

      The minimum voltage immediately after cranking is 8.92 V or higher and the voltage approximately 0.03 seconds after the ST NO. 1 relay is turned ON is approximately 8.92 V or higher

      Tip:

      Check the value of the following Data List items at the same time.

      • Data List [Min Voltage(Cranking)]: 7.65 V or higher*1, 8.92 V or higher*2

      • Data List [Min Volt(After Cranking)]: 7.66 V or higher*1, 8.92 V or higher*2

      • *1: Specified battery

      • *2: Non-specified battery

    Result

    Proceed to

    OK

    NG
    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

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    NG

    CHECK BATTERY

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