An ACDelco GM Original Equipment Ignition Knock (Detonation) Sensor monitors the engine for pinging or spark knock, and is a GM-recommended replacement for your vehicle's original component. The sensor creates a voltage signal based on the vibrations caused by erratic air/fuel mixture combustion; the engine control module uses this signal to adjust the ignition timing and air/fuel mixture. This original equipment ignition knock sensor has been manufactured to fit your GM vehicle, providing the same performance, durability, and service life you expect from General Motors.