LANE-KEEP ASSIST SYSTEM [(E)]

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Purpose

•  The lane-keep assist system provides steering assistance to help the driver stay within the vehicle lane if the vehicle might be deviating.
•  The forward sensing camera (FSC) detects the white lines (yellow lines) of the vehicle lane in which the vehicle is traveling and if the system determines that the vehicle may deviate from its lane, it operates the electric power steering to assist the driver’s steering operation.
Warning
•  The lane-keep assist system is not an automated driving system. In addition, the system is not designed to compensate for a driver’s lack of caution, and over-reliance on the system could lead to an accident.
•  The functions of the lane-keep assist system have limitations. Always stay on course using the steering wheel and drive with care.
•  Do not use the lane-keep assist system under the following circumstances, otherwise it may result in an accident.
―  The vehicle is driven on slippery roads such as icy or snow-covered roads, and unpaved roads
―  Tires of a different specified size are used, such as a temporary spare tire
―  Tires with insufficient tread are used
―  The tire pressures are not adjusted to the specified pressure
―  The vehicle is being used to tow a camper or boat trailer
―  Tire chains are used
―  The vehicle is driven on roads with lane lines other than white (yellow) lines, such as an expressway
Caution
•  Heed the following cautions so that the lane-keep assist system can operate normally.
―  Do not modify the vehicle’s suspensions
―  Always use wheels of the specified type and size for the front and rear wheels.
Note
•  The lane-keep assist system may not operate normally under the following conditions.
―  The white (yellow) lane lines are less visible because of dirt or paint flaking
―  The white (yellow) lane lines are less visible because of bad weather (rain, fog, or snow)
―  The vehicle is driven on a temporary lane or section with a closed lane resulting from construction where there might be multiple white (yellow) lane lines, or they are interrupted
―  The camera picks up an obscure line, such as a temporary line being used for construction, or because of shade, unmelted snow, or grooves filled with water
―  The surrounding brightness suddenly changes such as when entering or exiting a tunnel
―  Back-light is reflected off the road surface
―  The road surface is wet and shiny after rain, or there are puddles on the road
―  The width of a lane is excessively narrow
―  The vehicle is driven on roads with tight curves
―  Heavy luggage is loaded in the luggage compartment or on the rear seat causing the vehicle to tilt
―  The vehicle is driven through a fork in the road or a junction
―  The shade of a guardrail parallel to a white (yellow) lane lines is cast on the road
―  The illumination of the headlights is weakened because of dirt or the optical axis is deviated at night
―  The road is excessively uneven
―  The vehicle is shaken after hitting a road bump
―  A vehicle in front of your vehicle is running near a white (yellow) lane line making it less visible
―  The windshield is dirty or foggy
―  Strong light is directed from the front of the vehicle (such as sunlight, or headlights (high-beam) of on-coming vehicles)

Structural View

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Functions

•  The body control module (BCM) and EPS control module performs the steering wheel operation assist and activates the lane-keep assist system based on the white lines (yellow lines) recognized by the forward sensing camera (FSC). For details on the forward sensing camera (FSC), refer to the [FORWARD SENSING CAMERA (FSC)]. (See FORWARD SENSING CAMERA (FSC) [(E)].)
•  With the lane-keep assist system, operation of the steering wheel operation assist can be turned on or off.For details on the personalization features, refer to the [PERSONALIZATION FEATURES]

Steering wheel operation assist

•  When the system determines that the vehicle might be deviating from its lane, the steering wheel operation assist operates.
•  The system notifies the driver of the direction in which the system provided steerng wheel operation assistance on the multi-information display.


Lane-keep assist system warning

•  If the steering wheel operation assist operates with the following condition, the notification and warning speaker (front) sounds a warning.
―  Steering wheel operation assist continues more than 10 seconds
―  Another steering wheel operation assist is performed and the driver does not operate the steering wheel within 180 seconds after the first steering wheel operation assist
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Operation


System Wiring Diagram

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Block Diagram

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•  The lane-keep assist system operates when all of the following conditions are met.
―  Lane-keep assist system ON
―  Driving at vehicle speed of approx. 60 km/h {37 mph} or more
―  The system detects white lines (yellow lines) of the left or right
―  DSC is on
•  Even if the lane-keep assist system is on, the lane-keep assist system goes on stand-by under any of the following conditions.
―  Vehicle speed is less than approx. 55 km/h {34 mph}
―  The system cannot detect white (yellow) lane lines (left and right)
―  The turn signal lever is operated
―  The accelerator pedal is depressed abruptly
―  The brake pedal is operated
―  The steering wheel is operated
―  The DSC/TSC is operating
―  The DSC is turned off
•  The lane-keep assist system determines that the driver is performing the following driving operations, and suppresses the steering wheel operation assist.
―  The turn switch is operated.
―  Avoidance maneuver is performed or the vehicle lane is changed.
―  The accelerator pedal is depressed a certain amount or more.
―  The brake pedal is depressed.
Note
•  When all of the operation conditions are met after driving, the lane-keep assist system is enabled automatically.
•  If there is a malfunction in the lane-keep assist system or forward sensing camera (FSC) or EPS control module, the lane-keep assist system turns off.
•  When i-ACTIVSENSE switch*1 / i-ACTIVSENSE OFF switch*2 is operated with the lane-keep assist system turned on, the lane-keep assist system turns off.
*1:With i-ACTIVSENSE switch
*2:With i-ACTIVSENSE OFF switch

System conditions display table

Lane-keep assist system condition

Condition

i-ACTIVSENSE status symbol

i-ACTIVSENSE OFF symbol

i-ACTIVSENSE warning light

Multi-information display indication

Active driving display indication
OFF
System off
No display
No display
No display
No display
ON
Operating condition not met
Off
Off
No display
No display
Operating condition met, but the vehicle lane lines are not recognized
Off
Off
No display
No display
Operating condition met and the vehicle lane lines recognized on left side
Off
Off
No display
No display
Operating condition met and the vehicle lane lines recognized on right side
Off
Off
No display
No display
Operating condition met and the vehicle lane lines recognized on both sides
Off
Off
No display
No display
Steering assist rotated clockwise
Off
Off
No display
Steering assist rotated counter clockwise
Off
Off
No display
Function stopped temporarily
Off
Off
No display
No display
Mafunction occurred
Off
On
No display


Steering wheel operation assist

•  When the vehicle approaches to white lines (yellow lines), the body control module (BCM) calculates the steering wheel angle required for the prevention of a lane departure and outputs a steering wheel angle request signal to the EPS CM.
•  The EPS CM energizes the EPS motor to generate assist torque and supplement the insufficient steering angle for the prevention of a lane departure based on the steering wheel operation assist request signal.
•  When the driver performs the prevention operation during steering wheel operation assist, the driver's operation is given priority.
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Note
•  When the forward sensing camera (FSC) can detect either left or right white line (yellow line), the lane-keep assist system is performed. However, the steering wheel operation assist cannot be activated only when the vehicle deviates on the side where the white line (yellow line) is being detected.