LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2016 >> IS 350 Base, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Drivers Assistance Systems - ADAS >> Lane Departure Alert System - Diagnostics - Introduction >> Lane Departure Alert System >> System Description [04/2013 - 10/2016] >> System Description [04/2013 - 10/2016]

System Description [04/2013 - 10/2016]

  1. LANE DEPARTURE ALERT DESCRIPTION 
    1. The lane departure alert system uses the lane departure warning camera's image of the road in front to detect lane markers on either side of the vehicle. If the system detects that the vehicle is about to move out of its lane, the system uses the warning buzzer and multi-information display to warn the driver.

      However, in the following conditions, the lane departure alert system may not function normally.

      • When driving through an area with no lane markers, such as a tollbooth, a crossing or before a ticket checkpoint
      • When driving on a sharp curve
      • When lane markers are extremely narrow or extremely wide
      • When the vehicle leans to one side an unusual amount due to a heavy load or improper tire inflation pressure
      • When the following distance between your vehicle and the vehicle ahead is extremely short
      • When the lane markers are yellow (These may be more difficult for the system to recognize compared to white markers.)
      • When the lane markers are broken, Botts' dots (raised pavement markers) or stones
      • When the lane markers are on a curb etc.
      • When lane markers are obscured or partially obscured by sand, dirt, etc.
      • When there are shadows on the road running parallel with lane markers, or if a shadow covers the lane markers
      • When driving on a particularly bright road surface, such as concrete
      • When driving on a road surface that is bright due to reflected light
      • When driving in a location where the light level changes rapidly, such as the entrance to or exit from a tunnel
      • When sunlight or the headlights of oncoming vehicles are shining directly into the camera lens
      • When driving on roads that are branching or merging
      • When driving on a road surface that is wet due to rain, previous rainfall, standing water, etc.
      • When the vehicle experiences strong up-and-down motion such as when driving on an extremely rough road or on a seam in the pavement
      • When headlight brightness at nighttime is reduced due to dirt on the lenses, or when the headlights are misaligned
      • When driving on winding roads or roads that are uneven
      • When driving on rough or unpaved roads
  2. SYSTEM OPERATION 
    1. Lane departure warning function:

      The lane departure warning function operates when the lane departure alert main switch is on, the vehicle speed is between 50 km/h (32 mph) and 200 km/h (124 mph), and lane markers on the road surface are detected. With the departure warning function operating, if the vehicle is about to move out of the lane and this is detected by the lane departure warning camera, the system uses the warning buzzer and the multi-information display to warn the driver.

      HINT: 

      This function only provides suggestions for lane departure avoidance. This function does not automatically move the vehicle back into the lane.

      1. If any of the following conditions are met while the lane departure alert system is operating, system operation will be interrupted.
        Lane Departure Warning Function Operation Interruption Condition Lane Departure Warning Function Operation Return Condition
        When vehicle speed is less than 45 km/h (28 mph), or more than 200 km/h (124 mph) When vehicle speed is between 50 km/h (32 mph) and 200 km/h (124 mph)
        When turn signal light switch is operated When turn signal light switch is turned off
        When lane departure warning camera cannot detect lane markers When lane departure warning camera can detect lane markers
        After lane departure warning has been issued When the vehicle moves back into its lane, or a few seconds have passed since warning was issued
      2. If any of the following conditions are met while the lane departure alert system is operating, system operation will be suspended.
        Lane Departure Warning Function Operation Suspension Condition Lane Departure Warning Function Operation Restart Condition
        When lane departure alert main switch is turned off When lane departure alert main switch is turned on
        When system operation is interrupted When the system returns to normal
        When the system is malfunctioning When the engine switch is turned on (IG), normal system operation is confirmed
      3. If the following condition is met, the lane departure warning camera sounds a warning buzzer, turns off the lane departure alert indicator, displays "LDA not available" on the multi-information display, and temporarily suspends lane departure alert system operation.
        • A high lane departure warning camera temperature is detected.
        GTY460900Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. If the following condition is met, the lane departure warning camera sounds a warning buzzer, turns off the lane departure alert indicator, displays "Check LDA System" on the multi-information display, and suspends lane departure alert system operation.
        GTY461046Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
        • Lane departure alert system is malfunctioning
  3. FUNCTION OF MAIN COMPONENTS 
    W/ DYNAMIC RADAR CRUISE CONTROL SYSTEM:

    Item Outline
    Lane Departure Warning Camera
    • Takes an image of the road ahead and processes the image. Based on the results, display information and a buzzer request signal are sent to the combination meter assembly
    • Controls display information for the multi-information display and buzzer sound condition
    • Monitors the lane departure alert system malfunctions and records diagnostic information
    Driving Support ECU Assembly Sends the operation condition of the lane departure alert main switch to the lane departure warning camera
    Steering Pad Switch Assembly
    • Lane Departure Alert Main Switch
    Turns the lane departure alert system on/off
    Headlight Dimmer Switch Assembly Sends the operation condition of the turn signal light switch to the lane departure warning camera
    Combination Meter Assembly
    • The lane departure alert indicator turns on when the lane departure alert system main switch is on
    • When the lane departure alert system detects a malfunction, the warning buzzer sounds once to inform the driver
    • In response to the multi-information display signal from lane departure warning camera, lane markers are displayed to inform the driver of lane detection
    • When the lane departure warning camera detects a malfunction signal, a message is displayed on the multi-information display to inform the driver
    Yaw Rate Sensor Detects the yaw rate of the vehicle and transmits a signal to the lane departure warning camera
    Skid Control ECU (Brake Actuator Assembly) Sends vehicle speed information to the lane departure warning camera
    Vehicle Speed Sensor Sends a vehicle speed signal to the skid control ECU (brake actuator assembly), and then to the lane departure warning camera
    Skid Control Buzzer Assembly Sounds a buzzer upon receiving a signal from the lane departure warning camera
    ECM Sends a shift position R signal to the lane departure warning camera
    Main Body ECU (Multiplex Network Body ECU) Sends country specification information to the lane departure warning camera
    W/O DYNAMIC RADAR CRUISE CONTROL SYSTEM:

    Item Outline
    Lane Departure Warning Camera
    • Takes an image of the road ahead and processes the image. Based on the results, display information and a buzzer request signal are sent to the combination meter assembly
    • Controls display information for the multi-information display and buzzer sound condition
    • Monitors the lane departure alert system malfunctions and records diagnostic information
    • Monitors the lane departure alert main switch signal
    Steering Pad Switch Assembly
    • Lane Departure Alert Main Switch
    Turns the lane departure alert system on/off
    Headlight Dimmer Switch Assembly Sends the operation condition of the turn signal light switch to the lane departure warning camera
    Combination Meter Assembly
    • The lane departure alert indicator turns on when the lane departure alert system main switch is on
    • When the lane departure alert system detects a malfunction, the warning buzzer sounds once to inform driver
    • In response to the multi-information display signal from lane departure warning camera, lane markers are displayed to inform the driver of lane detection
    • When the lane departure warning camera detects a malfunction signal, a message is displayed on the multi-information display to inform the driver
    Yaw Rate Sensor Detects the yaw rate of the vehicle and transmits a signal to the lane departure warning camera
    Skid Control ECU (Brake Actuator Assembly) Sends vehicle speed information to the lane departure warning camera
    Vehicle Speed Sensor Sends a vehicle speed signal to the skid control ECU (brake actuator assembly), and then to the lane departure warning camera
    Skid Control Buzzer Assembly Sounds a buzzer upon receiving a signal from the lane departure warning camera
    ECM Sends a shift position R signal to the lane departure warning camera
    Main Body ECU (Multiplex Network Body ECU) Sends country specification information to the lane departure warning camera