2010 Lexus IS 250 Owners Manual - Page 271
2010 Lexus IS 250 Manual
Page 271 highlights
2-4. Using other driving systems Driving in vehicle-to-vehicle distance control mode This mode employs a sensor to detect the presence of vehicles up to approximately 400 ft. (120 m) ahead and to judge the distance between your vehicle and those the vehicle ahead of you. Note that vehicle-to-vehicle distance will close in when traveling on long downhill slopes. 2 When driving Example of constant speed cruising When there are no vehicles ahead The vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle distance can also be set by operating the vehicle-to-vehicle distance control. Example of deceleration cruising When the vehicle ahead is driving slower than the set speed When a vehicle is detected running ahead of you, the system automatically decelerates your vehicle. When a greater reduction in vehicle speed is necessary, the system applies the brakes. A warning tone warns you when the system cannot decelerate sufficiently to prevent your vehicle from closing in on the vehicle ahead. 191