California Turbo Diesel Series

The fuel rack position sensor consists of an iron core, 2 coils (differential and reference coil) and 2 short circuit rings. It is connected to the ECU with a 3-pole plug.

The 2 coils are attached to an iron core which is assembled to the housing. The short circuit ring is connected to the fuel rack and moves along with it around the lower leg of iron core without touching it. The reference coil and the short circuit ring are located on the upper leg.

The reference coil with the short circuit ring produce a constant inductance value for reference. The distance between the short circuit ring and the measuring coil changes in accordance with the fuel rack position. The resulting variable inductance is compared with the reference value, from which the ECU unit determines the fuel rack position.