LANE DEPARTURE ALERT SYSTEM


  1. FUNCTION OF MAIN COMPONENTS

    Components Function
    Pre-crash Safety City Sensor PCC ECU

    • Controls the lane departure alert system.

    • Transmits the indicator illumination request signal and buzzer sound request signal to the combination meter assembly.

    • Transmits an operation signal to the pre-crash safety city heater via the pre-crash safety city heater relay.*
    Monocular Camera Sensor

    • Captures a view of the road ahead of the vehicle and detects lane markers on the driving lane, and calculates the radius to the center of the lane, lane width and distance from markers and heading angle deviation.
    Pre-crash Safety City Heater* Heats the heater pattern area in accordance with the signals from the pre-crash safety city sensor.
    Steering Pad Switch Assembly LDA Main Switch

    • Transmits an on/off signal to the pre-crash safety city sensor.
    Combination Meter Sub-assembly Combination Meter

    • Transmit the turn signal state to pre-crash safety city sensor.
    LDA Indicator Light

    • Illuminates or turns off in accordance with signals from the pre-crash safety city sensor.

    • When the system is normal and green lights, when the system suspended or failure will light yellow.
    Lane Marker Indicator Light (Left)

    • Illuminates or turns off in accordance with signals from the pre-crash safety city sensor.

    • When the pre-crash safety city sensor recognizes the lane marker on the left side, the line turns on green and flashes yellow when deviation from the traffic lane is detected. Also, it will light yellow when there is a system malfunction.
    Lane Marker Indicator Light (Right)

    • Illuminates or turns off in accordance with signals from the pre-crash safety city sensor.

    • When the pre-crash safety city sensor recognizes the lane marker on the right side, the line turns on green and flashes yellow when deviation from the traffic lane is detected. Also, it will light yellow when there is a system malfunction.
    Buzzer Sounds to warn the driver of the system condition in accordance with signals from the pre-crash safety city sensor.
    Airbag Sensor Assembly Yawrate Sensor Detects yaw rate and transmits a signal to the pre-crash safety city sensor.
    Brake Booster with Master Cylinder Assembly Skid Control ECU Sends a vehicle speed signal from the speed sensor to the pre-crash safety city sensor.
    Headlight Dimmer Switch Assembly Transmits a turn signal command to the combination meter assembly.
    Speed Sensor Transmits a vehicle speed signal to the skid control ECU.

    *: Models with pre-crash safety city heater

  2. FUNCTION


    1. Pre-crash Safety City Sensor


      1. The pre-crash safety city sensor captures a road image up to approximately 50 m (164 ft.) ahead of the camera.

      2. The pre-crash safety city sensor detects lane markers and calculates the radius to the center of the lane, the vehicle center position disparity among the distances from each left and right lane marker and the angle disparity between the vehicle traveling direction and each left and right lane marker.

      3. When one of the following operations is conducted, the pre-crash safety city sensor angle must be adjusted. For details, refer to the Repair Manual.


        • The pre-crash safety city sensor is removed and reinstalled or replaced.

        • Parts relating to the tires or suspension are replaced or adjusted.

        • Excessive force is applied to the pre-crash safety city sensor.

      4. The pre-crash safety city sensor calculates the estimated position which the front wheel will reach based on the information collected, vehicle speeds and front wheel positions. When the pre-crash safety city sensor determines that the front wheel is about to cross the lane marker, the pre-crash safety city sensor activates the lane departure alert system, displays a warning indicator on the combination meter assembly and sounds the buzzer.

      5. The lane departure alert system does not operate if the vehicle approaches the lane marker at a shallow angle, but does not cross it.

        A0046I6E03
        Text in Illustration
        *1 Pre-crash Safety City Sensor *2 Monocular Camera Sensor
        *a Image Processing Range *b Lane Marker
        *c Approximately 3.0 m (9.8 ft.) or more *d Approximately 50 m (164 ft.)
        A0046LRE01
        Text in Illustration
        *a Image Captured by Pre-crash Safety City Sensor *b Left Lane Marker
        *c Center of Lane *d Right Lane Marker
        *e Angle between the vehicle traveling direction and right lane marker. *f Distance from the center of vehicle to right lane marker.
        *g Distance from the center of vehicle to left lane marker. *h Angle between the vehicle traveling direction and left lane marker.
        *i Lane Radius (If only the left lane marker or right lane marker is recognized, the radius of the recognized lane marker will be calculated.) - -

    2. Pre-crash Safety City Heater (Models with Pre-crash Safety City Heater)


      1. The pre-crash safety city heater, which is installed between the pre-crash safety city sensor and windshield glass, is heated in the heater pattern area according to signals from the pre-crash safety city sensor in order to prevent the windshield glass on the front of the pre-crash safety city sensor from fogging, and also to remove fog buildup.

  3. OPERATING CONDITION


    1. Operating Conditions of Lane Departure Alert System

      Operation Condition
      Operating/Resume

      The lane departure alert system is activated when all of the following conditions are met:


      • The LDA main switch is on. (When the LDA main switch is pressed to turn on the lane departure alert system, the LDA indicator light illuminates.)

      • The vehicle speed is approximately 50 km/h (32 mph) or more.

      • Lane markers are detected.

      • No turn signal command is detected.

      • System malfunction is not detected.
      Suspended

      The lane departure alert system is suspended when any one of the following conditions is met:


      • The vehicle speed is lower than 50 km/h (32 mph).

      • A turn signal command is detected.

      • No lane markers are detected.

      • The temperature of the pre-crash safety city sensor is abnormal.

      • Immediately after the lane departure alert is activated.
      Canceled

      The lane departure alert system is stopped when any one of the following conditions is met:


      • The LDA main switch is off.

      • The lane departure alert system is malfunctioning.

      The lane departure alert system resumes when the following conditions are met:


      • The conditions to start operation listed above are satisfied.

      • The lane departure alert system condition returns to normal.

      • The ignition switch turned off and ON again to ensure normal operation, after the lane departure alert system has been stopped by a system malfunction.

  4. OPERATION


    1. The pre-crash safety city sensor calculates the estimated position which the front wheel will reach based on the information collected, vehicle speeds and front wheel positions. When the pre-crash safety city sensor determines that the front wheel is about to cross the lane marker, the pre-crash safety city sensor activates the lane departure alert system, displays a warning indicator on the combination meter and sounds the buzzer.

    2. The lane departure alert system does not operate if the vehicle approaches the lane marker at a shallow angle, but does not cross it.

    3. Combination Meter Assembly


      1. Combination meter will display the operating state of the system by sounding the buzzer is changed and turns on or flashing indicator light color.

      2. Examples are shown below for the illumination or display of each indicator, warning light.

        A00469LE03
        Text in Illustration
        *a Lane Marker Indicator Light (Left) *b Lane Marker Indicator Light (Right)
        *c LDA Indicator Light - -
        Condition LDA Indicator Light Lane Marker Indicator Light Indicators Buzzer

        • Approximately 50 km/h (32 mph) or more

        • Lane Markers Detected

        		 Illuminates (Green) Both Illuminates (Green) A0046DX -

        • Approximately 50 km/h (32 mph) or more

        • One Lane Marker Detected

        		 Illuminates (Green) Illuminates (Green) A0046GJ -

        • Approximately 50 km/h (32 mph) or more

        • Warning Operating

        		 Illuminates (Green) Blinking (Yellow) A0046K4 Sounds 2 seconds maximum

        • Approximately 50 km/h (32 mph) or more

        • Lane Markers Not Detected

        		 Illuminates (Green) - A0046BE -
        System Malfunction Illuminates (Yellow) Illuminates (Yellow) A0046J7 -

  5. DIAGNOSIS


    1. When a failure is detected in the lane departure alert system, the pre-crash safety city sensor stop the lane departure alert system, the LDA indicator light , lane marker indicator light (Left) , as well as the lane marker indicator light (Right), all come on yellow, and the system notifies the driver of the problem.

    2. At the same time, the malfunction is stored in memory as a Diagnostic Trouble Code (DTC). When a Global Techstream (GTS) is connected to the DLC3, the DTC can be read. For details, refer to the Repair Manual.