110 Engine Speed Sensor Signal - Open Circuit: Function

Fig 1: Identifying Engine Speed Sensor Components

Courtesy of PORSCHE OF NORTH AMERICA, INC.

A soft iron core partially bundles the magnetic field produced by the permanent magnet which then enters the space and closes again through the magnetically conductive parts of the engine. A steel toothed ring moving past the face of the sensor affects the magnetic field. The change in the magnetic field induces an electric charge in the coil winding which is used by the DME control module.