Where is the engine speed sensor located on a vw golf?

The engine crankshaft has a toothed or slotted wheel called the crankshaft reluctor. It is located near the front. When rotating, the teeth on the reluctor pass in front of a fixed magnetic pickup or Hall-effect sensor. The rotating magnetic field induces a tiny voltage or electric current in the pickup every time a tooth passes in front of it. The pulses are then sent to the engine control unit (ECU) which measures the length of time between the pulses to determine the engine's rotational speed.