Car Knock Sensors

The car aftermarket knock sensor is an AC signal generator, which can detect the speed and position of the rotating shaft, vibration or mechanical pressure. It's also a piezoelectric device. They are made of special materials that can sense mechanical pressure or vibration, for example, AC voltage can be generated when the engine starts knocking.

When the engine vibrates or knocks, the piezoelectric ceramics produce a voltage peak. The greater the knock or vibration, the greater the peak. The engine control unit ECU processes the received signal from the automotive knock sensors. If it judges that knock occurs, it will delay the ignition time and prevent further knock. When ECU does not receive the signal from the automotive knock sensors, it will advance the ignition time to ensure the best power output of the engine.

The car knock sensor from MAPMS auto sensors provides knock signal to the ECU and reminds ECU to readjust the ignition timing to prevent further knock.

Knock Sensors Features

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Accurately measure engine shake.

Precise adjustment of ignition advance angle.

Durable and not easily damaged.

What Are the Symptoms of a Bad Auto Knock Sensor?

Auto Knock Sensor is used to measure the engine jitter and adjust the ignition advance angle when the engine produces knock. If there is a fault, the engine deflagration signal cannot be detected and the ignition time cannot be postponed automatically. Judge whether there is a fault through the following phenomena.

Knock Engine of automotive knock sensor

When the engine is working, engine knock will be caused by excessive ignition time advance (ignition advance angle), engine load, temperature and fuel quality. In case of knock, before the piston moves to TDC, the light one will produce noise and reduce the power of the engine, the heavy one will damage engine mechanical parts.

ECU Cannot Monitor the Degree of Deflagration

In case of damaged, ECU cannot monitor the degree of deflagration, it will reduce the ignition advance angle, when ECU detects that the engine has deflagration through the deflagration sensor, so it is wrongly judged that there is no deflagration. In this case, ECU will increase the ignition advance angle and cause the engine to work rough and shake due to deflagration.

Automatic Delay Ignition Time

Automatically delay the ignition time to prevent engine detonation. Therefore, the engine will be in the working state of ignition delay. The fuel consumption will increase, combustion energy rate will decrease, and engine power will decrease.

If you need any kinds of car spares and parts, please contact us, as one of the most professional auto spares suppliers, MAPMS is willing to offer you high quality products.