Buy 2008 Audi S4 Air Bag Impact Sensor (Rear). A4; Rear. Cabriolet S4; Side. Rear seat. S4, RS4; Rear - OEM Audi Part # 8E0959643B (8E0-959-643-B)

Sensor. Impact.
A Sensor to determine the location on the vehicle of Impact and the severity of the Impact to determine if and which air bags should be deployed. For. Air Bag. Ft. Side.

Air Bag Impact Sensor

Fits A4, RS4, S4

A4; Rear. Cabriolet S4; Side. Rear seat. S4, RS4; Rear.
Air Bag Crash Sensor - Repair or Replace
An airbag or SRS light can sometimes indicate a problem with the impact sensor on your 2008 Audi S4, particularly if it's been involved in a collision—at any speed. Have a technician inspect your vehicle's crash sensor.