2011 Toyota Prius Owners Manual - Page 285

2-4. Using other driving systems n Obstacles not detected The sensor cannot detect plastic obstacles such as pylons. There may also be occasions when the radar sensor cannot detect pedestrians, animals, bicycles, motorcycles, trees, or snowdrifts. n The pre-collision system is operational when l Pre-collision seat belts (linked to the radar sensor): • Vehicle speed is above 4 mph (5 km/h). • The speed at which your vehicle is approaching the obstacle or oncoming vehicle exceeds 19 mph (30 km/h). • The front occupants are wearing a seat belt. l Pre-collision seat belts (linked to brake operation): • Vehicle speed exceeds 19 mph (30 km/h). • The system detects sudden braking or skidding. • The front occupants are wearing a seat belt. l Pre-collision brake assist: • Vehicle speed is above 19 mph (30 km/h). • The relative speed difference between your vehicle and another vehicle that is ahead of your vehicle, or the speed at which your vehicle is approaching an obstacle is greater than 19 mph (30 km/h). • The brake pedal is depressed. l Pre-collision braking: • The pre-collision braking off button is not pressed. • Vehicle speed is above 10 mph (15 km/h). • The relative speed difference between your vehicle and another vehicle that is ahead of your vehicle, or the speed at which your vehicle is approaching an obstacle is greater than 10 mph (15 km/h). 2 When driving 259 PRIUS_U (OM47685U) DVD