2007 Lexus IS 250 Owners Manual - Page 167

2-4. Using other driving systems PCS (Pre-Collision System) (if equipped) Safety systems such as the brakes and seat belts are automatically engaged to lessen impact and injuries to occupants as well as vehicle damage when the radar sensor detects an unavoidable frontal collision. n Pre-collision seat belts The seat belts are immediately retracted as the effect of the pretensioner is increased (→P. 35), to provide even greater constraining force to protect the driver and passengers. In the event of sudden braking or skidding, the system will operate even if no obstacle has been detected. n Pre-collision brake assist Applies greater braking force in relation to how strongly the brake pedal is depressed. Radar sensor Detects vehicles or other obstacles on or near the road ahead and determines whether a collision is imminent based on the position, speed, and heading of the obstacles. Grille cover Radar sensor n Obstacles not detected The sensor cannot detect plastic obstacles such as pylons. There may also be occasions when the sensor cannot detect pedestrians, animals, bicycles, motorcycles, trees, or snowdrifts. 154