While camshaft position sensors can vary in their design, many of them are magnetic. This is because a magnetic field can be used to detect the position of the camshaft. The sensor usually consists of a magnet and a coil of wire. When the camshaft turns, the magnet moves with it. This movement changes the magnetic field, which induces a voltage in the coil of wire. This voltage can then be used to determine the position of the camshaft.