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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Engine Mechanical >> Starter >> Stop And Start System - Circuit Tests & Symptom Tests (3 Of 3) >> Stop And Start System >> After Engine Stops due to Stop and Start System, Engine does not Restart [10/2022 - ] >> Caution / Notice / Hint

Caution / Notice / Hint

  1. PRECAUTIONS WHEN THE ENGINE STOP AND START ECU AND THE STARTER ASSEMBLY ARE REPLACED 
    NOTE:
    • When the engine stop and start ECU is replaced, it is necessary to read the number of starter operations before replacement and store this number in the new engine stop and start ECU after replacement, and to perform external backup boost converter (eco run vehicle converter assembly) existence learning. Moreover, initialization/learning of the air conditioning information and initialization/learning of the deceleration sensor zero point are also required.

      Refer to REGISTRATION [10/2022 - 11/2023] , or refer to REGISTRATION [11/2023 - ]

    • When the starter assembly is replaced, the number of starter operations stored in the engine stop and start ECU must be reset.

      Refer to REGISTRATION [10/2022 - 11/2023] , or refer to REGISTRATION [11/2023 - ]

    • When the starter assembly is replaced, "ST relay" must be also replaced.
    • Inspect the fuses for circuits related to this system before performing the following procedure.
  2. PRECAUTIONS WHEN BATTERY IS DISCHARGED AFTER LEAVING VEHICLE FOR A LONG TIME 

    HINT: 

    If the vehicle has not been used for a long time, the battery charge may be low and stop and start control operation may be prohibited. After recharging the battery until the charging current decreases to 5 A or below, if the integrated current value still does not increase to the threshold value*1 or above, initialize the integrated current value*2 and drive the vehicle approximately 5 to 40 minutes until stop and start control operates.

    1. *1: For information about the integrated current threshold value, refer to the system description.

      Refer to SYSTEM DESCRIPTION [10/2022 - 11/2023] , or refer to SYSTEM DESCRIPTION [11/2023 - ]

    2. *2: Use the GTS to perform Integrated Current Value Initialization.

      Refer to REGISTRATION [10/2022 - 11/2023] , or refer to REGISTRATION [11/2023 - ]

  3. PRECAUTIONS WHEN CONNECTING/DISCONNECTING CABLE TO/FROM NEGATIVE BATTERY TERMINAL 
    NOTE:

    When the engine stop and start ECU or oil pump with solenoid assembly is replaced, check the oil pump with solenoid assembly.

    Refer to REGISTRATION [10/2022 - 11/2023] , or refer to REGISTRATION [11/2023 - ]

    HINT: 

    • If the cable is disconnected from the battery terminal, stop and start control is prohibited until refresh charge is completed. In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item Status of Battery Charge Control changes from "Refresh Charge Mode". (Usually, idling the engine for 5 to 60 minutes with the battery fluid temperature at 11°C (52°F) or higher, the refresh charge will be completed.)
    • If the GTS is not available and the Data List item Status of Battery Charge Control cannot be checked, charge the battery by idling the engine for approximately 5 to 60 minutes or driving the vehicle, and then drive the vehicle and check that stop and start control operates. If the engine is started with the hood open, the system determines that a jump start has occurred. Therefore, make sure that the hood is closed before starting the engine and driving the vehicle.
    • After the refresh charge completes, turn the ignition switch off, wait for at least 30 seconds, and then start the engine again. If the vehicle enters refresh charge mode again while the engine is idling, the initial refresh charge did not properly complete, so wait for the refresh charge to complete.
      1. If power is not supplied to the navigation system or audio and visual system when the ignition switch is turned to ON for the first time after the battery has been reconnected, vehicle control history code X087A will be stored. Perform either of the following operations:
        1. Turn the ignition switch from ON to off twice.
        2. After turning the ignition switch from ON to off, clear the DTCs.
        3. Enter the following menus: Powertrain / Stop and Start / Utility / Vehicle Control History (RoB) / Clear.
          NOTE:

          By performing this procedure, all stored Vehicle Control History items will be cleared.

  4. IF THE ENGINE FAILS TO RESTART FROM IDLING STOP 
    NOTE:

    If the engine fails to restart when stopped by stop and start control, the brake actuator may be activated. Brake actuator activation conditions: 

    • When the engine fails to restart when stopped by stop and start control.
    • When the brake booster vacuum is insufficient.
    • When the vehicle speed is 3 km/h (2 mph) or more and the brake pedal is depressed*.
      1. *: When the engine is not running.

    HINT: 

    • When the engine fails to restart when stopped by stop and start control and the brake booster vacuum is insufficient, the brake actuator is activated to ensure the braking force. When the brake actuator is activated, sound and vibration may be generated. This is not due to malfunction of the stop and start system or the vehicle.
  5. PRECAUTIONS FOR FOUR-WHEEL TOWING 

    Do not tow the vehicle with all 4 wheels on the ground.

    NOTE:
    • Towing the vehicle with all 4 wheels on the ground may have a detrimental effect on the stop and start system, and could lead to damage.

    HINT: 

    If it is absolutely necessary to tow the vehicle with all 4 wheels on the ground, before towing first turn the ignition switch off. Then, turn the ignition switch to ON without starting the engine, and tow the vehicle.

  6. PRECAUTIONS WHEN REPLACING ECM 
    NOTE:

    When the ECM is replaced on a vehicle with a non-specified battery, it is necessary to perform battery type switching.

    Refer to REGISTRATION [10/2022 - 11/2023] , or refer to REGISTRATION [11/2023 - ]

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