Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
System Description
- LANE-KEEPING ASSIST DESCRIPTION
- The lane-keeping assist system uses the object recognition camera's image of the road in front to detect lane marker on either side of the vehicle. If the system detects that the vehicle is about to move out of the lane marker, it uses the warning buzzer and multi-information display to warn the driver.
However, in the following conditions, the lane-keeping assist system may not function normally.
- Vehicle is near toll booths or similar areas
- Road has no lane marker
- Lane marker are cracked
- Road has yellow lines
- There is a shadow on either of the lane marker
- As a result of reflections, the road surface is bright
- Road has a reflective surface similar to concrete road
- Area where brightness changes suddenly, such as entrances and exits of tunnels or similar area
- Bright light is directed at sensor
- Incline of the road varies, winding road or other type of road where road surface is irregular
- Bad weather
- Frozen or snowy roads
- With water or other liquid on road surface
- The lane-keeping assist system uses the object recognition camera's image of the road in front to detect lane marker on either side of the vehicle. If the system detects that the vehicle is about to move out of the lane marker, it uses the warning buzzer and multi-information display to warn the driver.
- SYSTEM OPERATION
- Lane departure warning function:
The lane departure warning function operates when the lane-keeping assist main switch is on, the vehicle speed is 48 km/h (30 mph) or more, 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 driving support ECU, the ECU uses the warning buzzer and the multi-information display to warn the driver. Also, the ECU uses the electronic power steering system's motor to apply steering force and give suggestions to the driver for lane departure avoidance.
HINT:
This function only provides suggestions for lane departure avoidance. This function does not automatically move the vehicle within a lane.
Lane Departure Warning Function Operation Suspension Condition Restart Condition When vehicle speed is less than 48 km/h (30 mph) When vehicle speed is 48 km/h (30 mph) When turn signal light switch is operated When turn signal light switch is turned off When steering force above a specified amount is applied When steering force above a specified amount is not applied When windshield wiper switch is set to Lo or Hi When windshield wiper switch is turned off When lane recognition camera sensor cannot detect lane marker When lane recognition camera sensor can detect lane marker While brake pedal operation is being detected After brake pedal operation is completed After lane departure warning has been issued When the vehicle is back to its lane, or a few seconds have passed since warning was executed - Lane-keeping assist function:
The lane-keeping assist function operates when the lane-keeping assist main switch is on, the vehicle speed is approximately 72 to 180 km/h (45 to 112 mph), the dynamic radar cruise control system is ON. With the lane-keeping assist function operating, steering assistance is provided for the driver according to the driving conditions so that the vehicle stays near the midpoint of a lane. When the vehicle cannot be maintained within a lane and this is detected by the driving support ECU, the ECU uses the warning buzzer and the multi-information display to warn the driver. During the lane-keeping assist function operation, if any of the following conditions occur, the lane-keeping assist function will stop operating. If the condition is not longer detected, the lane-keeping assist function will automatically start operating again.
Lane-keeping assist function operation suspension condition Restart condition Object recognition camera cannot detect lane marker Object recognition camera sensor can detect lane marker Vehicle speed is not within 72 to 180 km/h (45 to 112 mph) Vehicle speed is within 72 to 180 km/h (45 to 112 mph) Turn signal light switch is operated Turn signal light switch is turned off Windshield wiper switch is set to Lo or Hi Windshield wiper switch is turned off Steering force above a specified amount is applied Steering force above specified amount is not detected Steering force above a specified amount does not occur* Steering operation is detected Lane change is performed Driving within a lane is confirmed HINT:
*: This refers to situations where the vehicle is driven for 15 seconds or more on a lane that is straight; or 5 seconds or more on a curved road (curve radius 1000 m (3281 ft.) or less).
- During the lane-keeping assist system operation, if any of the following conditions is detected, the lane-keeping assist system will stop operating.
- Dynamic radar cruise control system is canceled*
- Lane-keeping assist main switch is turned off
- object recognition camera's interior temperature is 65°C (149°F) or more
- Object recognition camera sensor's interior temperature is -35°C (-31°F) or less
- Electronic power steering system's operation limit is reached
- Lane-keeping assist system is malfunctioning
HINT:
*: During the lane-keeping assist function operation, if the dynamic radar cruise control system is canceled, the lane-keeping assist system will change from the lane-keeping assist function to the lane departure warning function.
- Lane departure warning function:
- FUNCTION OF MAIN COMPONENTS
Item Outline Object recognition ECU Based an the image from object recognition camera information such as lane width, road curvature, yaw angle and the amount of vehicle offset from the center of the lane is calculated and sent to the driving support ECU. Object recognition camera Takes image of road in front, and sends it to object recognition ECU Steering pad switch with modulator (Lane-keeping assist main switch) Turns lane-keeping assist system on/off Combination switch assembly Sends the operation condition of the windshield wiper switch and turn signal light switch signal to the driving support ECU. Power steering ECU assembly - Based on signal from driving support ECU, steering force is applied
- Sends driver's steering operation information to driving support ECU
Skid control ECU - Receives buzzer operation signal from driving support ECU, and sends it to skid control buzzer.
- Sends vehicle speed information to driving support ECU
Suspension control ECU Detects vehicle height condition, and sends information to driving support ECU Yaw rate sensor Detects yaw rate of vehicle and transmits its signal to driving support ECU Combination meter assembly (LKA indicator light) - Turns on when lane-keeping assists switch is on
- If driving support ECU detects malfunction, this light flashes to warn driver
Combination meter assembly (Buzzer) - When lane-keeping assist system detects malfunction, warning buzzer sounds once to inform driver.
- When hands-free driving is detected, buzzer sounds twice to information driver.
Combination meter assembly (Multi-information display) - When lane-keeping assist function is operating, steering wheel assistance is displayed in multi-information display to inform driver of control operation
- When lane-departure warning function is operating, lane marker are displayed to inform driver of lane detection
- When driving support ECU detects malfunction signal, multi-information display displays message to inform driver
Cruise control switch Turns cruise control system on/off Stop light switch assembly Detects depressing of brake pedal and transmits its signal to driving support ECU Skid control buzzer This buzzer sounds upon receiving signal from skid control ECU Vehicle speed sensor Sends vehicle speed signal to skid control ECU, and then it is sent to driving support ECU Driving support ECU - Based on lane marker information and information from other functions, driving support ECU sends signals to electronic power steering ECU so that it applies steering force
- Controls multi-information display's display information and buzzer sound condition
- Monitors lane-keeping assist malfunctions, and records diagnostic information
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.