Leak Detection Pump: Description and Operation

Fuel Supply, Low-pressure Side


Leak detection pump (LDP), for USA vehicles only

The functional principle for tank leakage diagnosis (LDP) is identical to that of the previous Cayenne vehicles. The complete fuel tank system is checked for possible leaks using the positive pressure method. This takes place only when the engine is running. The LDP is an electro-pneumatic diaphragm pump which is supplied with a vacuum. Evaluation by means of a reed contact switch located on the diaphragm takes place after the pumping phase.