LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2017 >> Prius Two >> Repair and Diagnosis >> External Pages >> Different car >> Section 5 (Automatic Headlight Beam Level Control System - Diagnostics - Introduction) >> Automatic Headlight Beam Level Control System >> Initialization [06/2021 - ] >> Initialization [06/2021 - ]
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Initialization [06/2021 - ]

WARNING: This page is about a different car, the 2022 Toyota Prius, 2021 Toyota Prius, 2020 Toyota Prius, and 2019 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
  • The necessary procedures (adjustment, calibration, initialization or registration) that must be performed after parts are removed and installed, or replaced during No. 1 headlight ECU sub-assembly LH removal/installation are shown below.
    Performed Work or System Condition Necessary Procedures Proceed to
    Replacement of the No. 1 headlight ECU sub-assembly LH Synchronize the vehicle information SYNCHRONIZE VEHICLE INFORMATION
    Perform No. 1 headlight ECU sub-assembly LH initialization NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH INITIALIZATION
    Replacement of the rear height control sensor sub-assembly LH, removal and reinstallation of the rear height control sensor sub-assembly LH, replacement of the suspension, etc. have been performed Perform No. 1 headlight ECU sub-assembly LH initialization NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH INITIALIZATION
    Auxiliary battery terminal is disconnected and connected. Steering Sensor Zero Point Calibration Refer to INITIALIZATION [07/2020 - ]
  • If the steering sensor zero point calibration is not performed, the AFS (adaptive front-lighting system) may not operate correctly.
  • A new No. 1 headlight ECU sub-assembly LH cannot operate until the vehicle information is registered.
  • After replacing the No. 1 headlight ECU sub-assembly LH, it is necessary to perform vehicle information registration and initialization.
  • Even if the No. 1 headlight ECU sub-assembly RH is replaced with a new one, vehicle information registration and initialization are not necessary.
  • Adjust the headlight aim after initializing the No. 1 headlight ECU sub-assembly LH.

    Refer to ADJUSTMENT [12/2018 - ]

  • When a malfunction is detected in the automatic headlight beam level control system, rear height control sensor sub-assembly LH signal initialization is impossible. Perform troubleshooting before initialization.
  • The automatic headlight beam level control system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to the How to Proceed with Troubleshooting procedure.

    Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2018 - ] 

  1. SYNCHRONIZE VEHICLE INFORMATION (When using the TECHSTREAM) 
    NOTE:
    • Make sure to synchronize the vehicle information before performing initialization.
    • If synchronization fails, make sure to turn the power switch off then back on (IG) before performing synchronization again.
    1. Turn the power switch off.
    2. Connect the Techstream to the DLC3.
    3. Turn the power switch on (IG).
    4. Check that the "Headlight System Uninitialized Visit Your Dealer" warning message is displayed on the multi-information display.
    5. Enter the following menus: Body Electrical / AFS / Utility / ECU Information Sync.

      Body Electrical > AFS > Utility 

      Tester Display
      ECU Information Sync
    6. Check the display on the Techstream and press "Next".
    7. Check that the "Headlight System Malfunction Visit Your Dealer" warning message continuously blinks 6 times at 2 Hz on the multi-information display.

      HINT: 

      • If the "Headlight System Malfunction Visit Your Dealer" warning message does not start blinking on the multi-information display after perform the procedure again.
      • If the "Headlight System Malfunction Visit Your Dealer" warning message changes from blinking to displayed on the multi-information display, the rear height control sensor sub-assembly LH may be malfunctioning.
    8. Press "Exit".
    9. Turn the power switch off.
      NOTE:

      After synchronizing the vehicle information, initialize the No. 1 headlight ECU sub-assembly LH.

  2. SYNCHRONIZE VEHICLE INFORMATION (When not using the TECHSTREAM) 
    NOTE:
    • Make sure to synchronize the vehicle information before performing initialization.
    • If synchronization fails, make sure to turn the power switch off then back on (IG) before performing synchronization again.
    1. Turn the power switch on (IG).
    2. Check that the "Headlight System Uninitialized Visit Your Dealer" warning message is displayed on the multi-information display.
    3. Using the headlight dimmer switch, turn the low beam headlights on and off 8 times within 20 seconds after turning the power switch on (IG).

      HINT: 

      If this step cannot be completed within 20 seconds, turn the power switch off. Then, turn the power switch on (IG) and restart the procedure.

    4. Check that the "Headlight System Malfunction Visit Your Dealer" warning message continuously blinks 6 times at 2 Hz on the multi-information display.

      HINT: 

      • If the "Headlight System Malfunction Visit Your Dealer" warning message does not start blinking on the multi-information display after perform the procedure again.
      • If the "Headlight System Malfunction Visit Your Dealer" warning message changes from blinking to displayed on the multi-information display, turn the power switch off and then on (IG). If "Headlight System Malfunction Visit Your Dealer" is displayed immediately after the power switch is turned on (IG), the rear height control sensor sub-assembly LH may be malfunctioning.
    5. Turn the power switch off.
      NOTE:

      After synchronizing the vehicle information, initialize the No. 1 headlight ECU sub-assembly LH.

  3. NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH INITIALIZATION (When using the TECHSTREAM) 
    NOTE:

    Make sure to synchronize the vehicle information before performing initialization.

    1. Prepare vehicle for initialization (w/ DRL OFF Switch)
      • Unload the vehicle, ensuring that the spare tire, tools and jack are in their original positions.
      • Check that there are no occupants in the vehicle.
      • Turn the light control switch to the DRL OFF position.
      • Stop the vehicle on a level surface and keep the vehicle height unchanged.
    2. Prepare vehicle for initialization (w/o DRL OFF Switch)
      • Unload the vehicle, ensuring that the spare tire, tools and jack are in their original positions.
      • Check that there are no occupants in the vehicle.
      • Turn the light control switch to the AUTO position.*
      • Stop the vehicle on a level surface and keep the vehicle height unchanged.

      HINT: 

      *: Turn off the headlights.

    3. Check the "Headlight System Malfunction Visit Your Dealer" warning message on the multi-information display.
      1. Turn the power switch on (IG), and check the condition of the "Headlight System Malfunction Visit Your Dealer" warning message on the multi-information display.

        OK

        Condition Specified Condition
        The No. 1 headlight ECU sub-assembly LH has been replaced with a new one. "Headlight System Malfunction Visit Your Dealer" blinks 6 times at 2 Hz.
        Replacement of the rear height control sensor sub-assembly LH, removal and reinstallation of the rear height control sensor sub-assembly LH, replacement of the suspension, etc. have been performed. "Headlight System Malfunction Visit Your Dealer" is not displayed.

        HINT: 

        If the condition of the "Headlight System Malfunction Visit Your Dealer" warning message is different than listed in the table above, the No. 1 headlight ECU sub-assembly LH or combination meter assembly (meter circuit plate) may be malfunctioning.

    4. Perform initialization.
      1. Turn the power switch off.
      2. Connect the Techstream to the DLC3.
      3. Turn the power switch on (IG).
      4. Enter the following menus: Body Electrical / AFS / Utility / Height Sensor Initialization.

        Body Electrical > AFS > Utility 

        Tester Display
        Height Sensor Initialization
      5. Check the display on the Techstream and press "Next".
      6. Check the proper "Position ID" by the fuel level according to the table below.
        GTY872497Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        *a Fuel Receiver Gauge

        HINT: 

        The "Position ID" is determined by the present fuel level as shown below.

        Fuel Level Position ID Number of Times Headlight Leveling Warning Blinks
        Within A range EMPTY 1
        Within B range 1/4 to over EMPTY 2
        Within C range 1/2 to over 1/4 3
        Within D range 3/4 to over 1/2 4
        Within E range FULL to over 3/4 5
      7. Select the proper "Position ID" and press "Next".
      8. Press "Exit".
      9. Check the condition of the "Headlight System Malfunction Visit Your Dealer" warning message on the multi-information display.

        Standard

        Condition Specified Condition
        The No. 1 headlight ECU sub-assembly LH has been replaced with a new one. Blinks 6 times at 2 Hz → Continuously blinks N* times at 2 Hz.
        Replacement of the rear height control sensor sub-assembly LH, removal and reinstallation of the rear height control sensor sub-assembly LH, replacement of the suspension, etc. have been performed. Off → Continuously blinks N* times at 2 Hz.

        HINT: 

        • *: The number of times that "Headlight System Malfunction Visit Your Dealer" warning message blinks is determined by the "Position ID" selected.
        • If the "Headlight System Malfunction Visit Your Dealer" warning message is displayed on the multi-information display, the No. 1 headlight ECU sub-assembly LH may be malfunctioning.
        • If initialization does not finish normally, restart the initialization procedure from step (i).
      10. Check that initialization finishes normally and turn the power switch off.

        HINT: 

        The warning message will blink in the pattern indicating that initialization has completed successfully continuously until the power switch is turned off.

  4. NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH INITIALIZATION (When not using the TECHSTREAM) 
    NOTE:

    Make sure to synchronize the vehicle information before performing initialization.

    1. Prepare vehicle for initialization (w/ DRL OFF Switch)
      • Unload the vehicle, ensuring that the spare tire, tools and jack are in their original positions.
      • Check that there are no occupants in the vehicle.
      • Turn the light control switch to the DRL OFF position.
      • Stop the vehicle on a level surface and keep the vehicle height unchanged.
    2. Prepare vehicle for initialization (w/o DRL OFF Switch)
      • Unload the vehicle, ensuring that the spare tire, tools and jack are in their original positions.
      • Check that there are no occupants in the vehicle.
      • Turn the light control switch to the AUTO position.*
      • Stop the vehicle on a level surface and keep the vehicle height unchanged.

      HINT: 

      *: Turn off the headlights.

    3. Check the "Headlight System Malfunction Visit Your Dealer" warning message on the multi-information display.
      1. Turn the power switch on (IG), and check the condition of the "Headlight System Malfunction Visit Your Dealer" warning message on the multi-information display.

        OK

        Condition Specified Condition
        The No. 1 headlight ECU sub-assembly LH has been replaced with a new one. "Headlight System Malfunction Visit Your Dealer" blinks 6 times at 2 Hz.
        Replacement of the rear height control sensor sub-assembly LH, removal and reinstallation of the rear height control sensor sub-assembly LH, replacement of the suspension, etc. have been performed. "Headlight System Malfunction Visit Your Dealer" is not displayed.

        HINT: 

        If the condition of the "Headlight System Malfunction Visit Your Dealer" warning message is different than listed in the table above, the No. 1 headlight ECU sub-assembly LH or combination meter assembly (meter circuit plate) may be malfunctioning.

    4. Perform initialization. (w/ DRL OFF Switch)
      1. Turn the power switch on (IG) and light control switch DRL OFF.
      2. Check the specified number of times to turn the low beam headlights on and off.
        GTY872497Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        *a Fuel Receiver Gauge

        HINT: 

        The number of times the low beam headlights need to be turned on and off is determined by the present fuel level as shown below.

        Fuel Level Number of Times to Turn Low Beam Headlights On and Off
        Within A range 1
        Within B range 2
        Within C range 3
        Within D range 4
        Within E range 5
      3. Enter initialization mode.
        1. Turn the power switch and light control switch to DRL OFF.
        2. Cover the automatic light control sensor with a lightproof object.
        3. Perform the following steps within 5 seconds.
          1. Press the power switch 2 times.

            HINT: 

            Turn the power switch on (IG).

          2. While pulling the headlight dimmer switch, turn it from DRL OFF to AUTO to DRL OFF again 3 times or more.

            HINT: 

            Check that the parking lights turn from off to on and back off again.

          3. Turn the light control switch to DRL OFF.

        HINT: 

        • Perform the above operation within 5 seconds.
        • When initialization mode has been entered, "Headlight System Malfunction Visit Your Dealer" warning message on the multi-information display starts blinking at 1 Hz.
      4. After entering initialization mode, turn the low beam headlights from off to on and back off again N* times.

        HINT: 

        • *: The number of times to turn the light control switch on and DRL OFF (N) is determined by the fuel level of the fuel receiver gauge.
        • Turn the light control switch on and DRL OFF within 20 seconds of entering initialization mode.
        • Turn the light control switch on and DRL OFF at intervals of approximately 3 seconds.
      5. Check the condition of the "Headlight System Malfunction Visit Your Dealer" warning message on the multi-information display.

        Standard

        Condition Specified Condition
        The No. 1 headlight ECU sub-assembly LH has been replaced with a new one. Blinks 6 times at 2 Hz → Continuously blinks N* times at 2 Hz.
        Replacement of the rear height control sensor sub-assembly LH, removal and reinstallation of the rear height control sensor sub-assembly LH, replacement of the suspension, etc. have been performed. Off → Continuously blinks N* times at 2 Hz.

        HINT: 

        • *: The number of times that "Headlight System Malfunction Visit Your Dealer" warning message blinks is determined by the number of times the low beam headlights are turned on and off.
        • If the "Headlight System Malfunction Visit Your Dealer" warning message is displayed on the multi-information display, the No. 1 headlight ECU sub-assembly LH may be malfunctioning.
        • If initialization does not finish normally, restart the initialization procedure from step (i).
      6. Check that initialization finishes normally and turn the power switch off.

        HINT: 

        The warning message will blink in the pattern indicating that initialization has completed successfully continuously until the power switch is turned off.

    5. Perform initialization. (w/o DRL OFF Switch)
      1. Turn the power switch on (IG).
      2. Check the specified number of times to turn the low beam headlights on and off.

        HINT: 

        The number of times the low beam headlights need to be turned on and off is determined by the present fuel level as shown below.

        Fuel Level Number of Times to Turn Low Beam Headlights On and Off
        Within A range 1
        Within B range 2
        Within C range 3
        Within D range 4
        Within E range 5
        GTY872497Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        *a Fuel Receiver Gauge
      3. Enter initialization mode.
        1. Turn the power switch and light control switch to AUTO.

          HINT: 

          Turn off the headlights.

        2. Shine a light on the automatic light control sensor.
        3. Perform the following steps within 5 seconds.
          1. Press the power switch 2 times.

            HINT: 

            Turn the power switch on (IG).

          2. While pulling the headlight dimmer switch, turn it from AUTO to tail to AUTO again 3 times or more.

            HINT: 

            Check that the parking lights turn from off to on and back off again.

          3. Turn the light control switch to AUTO.

        HINT: 

        • Perform the above operation within 5 seconds.
        • When initialization mode has been entered, "Headlight System Malfunction Visit Your Dealer" warning message on the multi-information display starts blinking at 1 Hz.
      4. After entering initialization mode, turn the low beam headlights from off to on and back off again N* times.

        HINT: 

        • *: The number of times to turn the light control switch on and AUTO (N) is determined by the fuel level of the fuel receiver gauge.
        • Turn the light control switch on and AUTO within 20 seconds of entering initialization mode.
        • Turn the light control switch on and AUTO at intervals of approximately 3 seconds.
      5. Check the condition of the "Headlight System Malfunction Visit Your Dealer" warning message on the multi-information display.

        Standard

        Condition Specified Condition
        The No. 1 headlight ECU sub-assembly LH has been replaced with a new one. Blinks 6 times at 2 Hz → Continuously blinks N* times at 2 Hz.
        Replacement of the rear height control sensor sub-assembly LH, removal and reinstallation of the rear height control sensor sub-assembly LH, replacement of the suspension, etc. have been performed. Off → Continuously blinks N* times at 2 Hz.

        HINT: 

        • *: The number of times that "Headlight System Malfunction Visit Your Dealer" warning message blinks is determined by the number of times the low beam headlights are turned on and off.
        • If the "Headlight System Malfunction Visit Your Dealer" warning message is displayed on the multi-information display, the No. 1 headlight ECU sub-assembly LH may be malfunctioning.
        • If initialization does not finish normally, restart the initialization procedure from step (i).
      6. Check that initialization finishes normally and turn the power switch off.

        HINT: 

        The warning message will blink in the pattern indicating that initialization has completed successfully continuously until the power switch is turned off.

scientia non olet · About LEMON Manuals