2023 BMW X5 Knock Sensor Replacement Cost

Every time the engine knock sensor notices a vibration, it sends a signal to the engine's computer, reporting how large it was. The engine's computer is programmed to expect a specified range of signals from the knock sensor. Most information from the knock sensor will be bumps in the road or closing the car door. However, when a vibration is large enough, the knock sensor signal will trigger the computer to alert the driver. This is a protective measure meant to prevent complete engine failure.

When a knock sensor fails, the engine may lack power, have poor acceleration, ping or knock on acceleration, and get poor fuel economy.

The Check Engine Light may illuminate with a fault code set for one or more knock sensors.