An accelerometer measures G-forces in one or more directions. In modern cars, these micro-sensors are placed throughout the chassis. They detect sudden impacts, body roll, and wheel bounce. This real-time data is used by safety, suspension, and stability control systems to keep the car stable and protect passengers.
The airbag module uses high-speed accelerometers to detect a crash. If the sensor registers a massive deceleration (such as hitting a wall at speed), the computer deploys the airbags in milliseconds. These sensors are calibrated to ignore minor bumps, driveway curbs, and slamming doors to prevent accidental deployments.
In active suspensions, accelerometers track how fast the wheels move up and down. The computer reads these movements and adjusts shock absorber damping in real time. This keeps the ride smooth over rough pavement and limits body lean in fast corners.