Impact sensors, also known as crash sensors, are important safety features for your vehicle. These sensors, located throughout your vehicle, detect a collision and trigger the airbags to go off. They are usually found at the front of the vehicle, behind the front fender, to detect a frontal impact, and in the side columns to detect a side impact. The exact number and location of airbag sensors you have will vary from one model to another, but those are the most frequently used locations.