Knock Sensor

This engine has two knock sensors. The knock sensors are located on left side on crankcase. The knock sensors detect the vibrations on the crankcase which occur due to injection and associated combustion in the individual cylinders.

Courtesy of NISSAN NORTH AMERICA, INC.

The vibrations on the crankcase are transmitted over a seismic mass on an inner piezo element and are converted into electrical voltage pulses.