2013 Toyota Sienna Owners Manual - Page 650

2-4. Using other driving systems The Rear Cross Traffic Alert function The Rear Cross Traffic Alert Functions when your vehicle is in reverse. It can detect other vehicles approaching from the right or left rear of the vehicle. It uses radar sensors to alert the driver of the other vehicle's existence through flashing the outside rear view mirror indicators and sounding a buzzer. 2 When driving Approaching vehicles Detection areas 349 SIENNA_OM_OM45472U_(U)