AFS (ADAPTIVE FRONT-LIGHTING SYSTEM) SYSTEM DESCRIPTION


  1. AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL


    1. General

      When the low beam headlights are on, the automatic headlight beam level control operates the headlight swivel motor in accordance with movement of the vehicle. The AFS ECU (headlight swivel ECU assembly) controls the system.

    2. Function of Main Components

      Component Outline
      AFS ECU (Headlight Swivel ECU Assembly) Receives various signals, calculates changes in the vehicle posture, and actuates the headlight swivel motor.
      Headlight Swivel Motor

      • Based on the signals received from the AFS ECU (headlight swivel ECU assembly), the motors move the reflectors in the headlight to vary the low beam.

      • Uses a stepper motor to precisely regulate the angle of the projector.
      Rear Height Control Sensor Sub-assembly Transmits a height control sensor signal to the AFS ECU (headlight swivel ECU assembly).
      Skid Control ECU Transmits speed sensor signals (front LH and RH) to the AFS ECU (headlight swivel ECU assembly).
      ECM Transmits an engine running status signal to the AFS ECU (headlight swivel ECU assembly).
      Main Body ECU (Multiplex Network Body ECU) Transmits a headlight status signal.
      Combination Meter Assembly When the system malfunctions, the combination meter assembly alerts the driver by flashing the AFS OFF indicator light in accordance with the signal from the AFS ECU (headlight swivel ECU assembly).

    3. Initial Set Control

      When the engine is started, the AFS ECU (headlight swivel ECU assembly) drives the headlight swivel motor and moves the headlight reflector to the lower limit position and returns it to the proper position. The AFS ECU (headlight swivel ECU assembly) thus assesses the position of the headlight for reference control.

      Note


      • Initialize the AFS ECU (headlight swivel ECU assembly) when the AFS ECU (headlight swivel ECU assembly) is replaced.

      • Initialize the AFS ECU (headlight swivel ECU assembly) (set the zero point of the height control sensor in the AFS ECU (headlight swivel ECU assembly)) after the vehicle height changes due to replacement of suspension components or after performing such operations as removal and reinstallation or replacement of the rear height control sensor sub-assembly.

  2. AFS (Adaptive Front-lighting System)


    1. General


      • An Adaptive Front-lighting System (AFS) is used in order to ensure a wide low beam lighting area and realize excellent visibility during turns by moving the low beam.

      • The AFS uses medium-to-high speed control and low speed control.

    2. Function of Main Components

      Component Outline
      AFS ECU (Headlight Swivel ECU Assembly) Receives various signals, calculates the target lighting angle, and actuates the headlight swivel actuator.
      Headlight Swivel Motor

      • Driven by the AFS ECU (headlight swivel ECU assembly), the motor moves the low beam left or right to the angle calculated by the AFS ECU (headlight swivel ECU assembly).

      • A stepper motor is used for the headlight swivel motor. The AFS ECU (headlight swivel ECU assembly) determines the low beam angle based on the number of steps (position) of the stepper motor.
      Steering Angle Sensor Detects the steering angle and direction and outputs signals to the AFS ECU (headlight swivel ECU assembly).
      Headlight Swivel Main Switch (AFS OFF Switch) Pressing this switch disables the operation of the AFS.
      Skid Control ECU Transmits speed sensor signals (front LH and RH) to the AFS ECU (headlight swivel ECU assembly).
      ECM

      • Transmits an engine running status signal to the AFS ECU (headlight swivel ECU assembly).

      • Transmits a shift position signal to the AFS ECU (headlight swivel ECU assembly). The AFS ECU (headlight swivel ECU assembly) determines whether the vehicle is moving forward or backward based on this signal.
      Main Body ECU (Multiplex Network Body ECU) Transmits a headlight status signal.
      Combination Meter Assembly AFS OFF Indicator Light When the system malfunctions, the combination meter assembly flashes the AFS OFF indicator light based on the signal from the AFS ECU (headlight swivel ECU assembly) to alert the driver.

    3. Low Speed Control


      • The AFS ECU (headlight swivel ECU assembly) performs low speed control when all of the following conditions are met:


        • Engine is running.

        • Vehicle is moving forward at a speed of 10 km/h (6 mph) or more.

        • Vehicle is moving forward at a speed of less than 30 km/h (19 mph).

        • Steering angle is 6° or more.

        • Low beam headlights are on.

        • AFS on/off condition is on.

      Swivel Angle Range
      Driving Condition Low Beam
      Left Right
      Right Turn 0° Fixed 0° to 10° to Right
      Left Turn 0° to 15° to Left 0° Fixed

    4. Medium-to-High Speed Control


      • The AFS ECU (headlight swivel ECU assembly) performs medium-to-high speed control when all of the following conditions are met:


        • Engine is running.

        • Vehicle is moving forward at a speed of 30 km/h (19 mph) or more.

        • Steering angle is 7.5° or more.

        • Low beam headlights are on.

        • AFS on/off condition is on.

      Swivel Angle Range
      Driving Condition Low Beam
      Left Right
      Right Turn 0° to 5° to Right 0° to 10° to Right
      Left Turn 0° to 15° to Left 0° to 7.5° to Left

    5. Operation Stop Condition


      • The AFS ECU (headlight swivel ECU assembly) stops performing control when any of the following conditions is met:


        • Engine is stopped.

        • Vehicle is moving forward at a speed of less than 10 km/h (6 mph).

        • Steering angle is less than 6°.

        • Low beam headlights are off.

        • AFS on/off condition is off.

        • Shift lever in R or N*1.


        • *1: for CVT or Multi-mode Manual Transaxle

    6. Initial Set Control

      When the engine is started, the AFS ECU (headlight swivel ECU assembly) operates the headlight swivel motors to confirm the initial position. The headlights are moved toward the center of the vehicle and then returned to their normal position. The AFS ECU (headlight swivel ECU assembly) does this to confirm the initial position of the headlights.

      Note


      • Initialize the AFS ECU (headlight swivel ECU assembly) when the AFS ECU (headlight swivel ECU assembly) is replaced.