The knock sensor is a component in the engine that detects and monitors the levels of engine knock or detonation. This sensor plays a vital role in ensuring the proper functioning of modern-day electronic control systems. It sends signals to the engine control module, which then make adjustments to the engine timing to prevent damage to the engine. Knock sensors are designed to help prevent engine damage, increase performance, and improve fuel efficiency. If the knock sensor is not functioning properly, it can cause the engine to misfire or the transmission to shift erratically. It's important to have it checked if you suspect any issues with your engine.