What is the reason for the EA888 reporting a knock signal that is too small?

[McGrant]

EA888 reporting a knock signal that is too small may be caused by poor fuel quality, fuel line issues, high engine operating temperature, sensor problems, sensor wiring faults, or the need for an engine computer upgrade or repair/replacement. Below are specific details about knock sensors: 1. There are many types of knock sensors, with the magnetostrictive knock sensor being the earliest type used, mainly composed of a magnetic core, permanent magnet, and induction coil. When the engine vibrates, the magnetic core shifts due to vibration, changing the magnetic flux within the induction coil and generating an induced electromotive force in the coil. 2. Other types, such as piezoelectric ceramic sensors, generate an electrical signal when the ceramic inside is squeezed due to engine vibration. Because this electrical signal is very weak, the connecting wires of knock sensors are usually wrapped with shielded cables.