Advanced Automatic Collision Notification

Advanced Automatic Crash Notification (AACN) is also known as Advanced Automatic Collision Notification and is the successor to Automatic Crash Notification (ACN). This system is found on a number of motor vehicles and is used to alert emergency services that a car accident has occurred and to automatically summon assistance.

When an accident has occurred (as determined by various sensors, airbag deployment, or seatbelt pretensioners), the AACN will initiate an emergency wireless call to a Telematics Service Provider (like Onstar) to deliver the vehicle's GPS location, crash-related data and open a voice communications channel to the emergency call center.

The Advanced ACN improves the data sent from the ACN version, as it include crash-severity data (including: speed, delta velocity, number of occupants and rollover data) as collected by in-vehicle sensors. This additional data could be used by emergency services providers to determine the quantity and type of rescue equipment that should be dispatched.