What is the function of a car knock sensor?

[LaDiana]

The function of a car knock sensor is: 1. To measure the degree of engine vibration and adjust the ignition timing when engine knocking occurs; 2. It is an AC signal generator that detects the speed and position of the crankshaft. The knock sensor includes: a magnetic core, permanent magnet, and induction coil. The working principle of a car knock sensor is: When vibration or knocking occurs, it generates a small voltage peak. The greater the knocking or vibration, the larger the peak voltage produced by the knock sensor. A certain high frequency indicates knocking or vibration. Knock sensors are typically designed to measure frequencies in the range of 5 to 15 kHz. When the control unit receives these frequencies, the computer adjusts the ignition timing to prevent further knocking.