The CP-Tester device is intended for supplying user-programmable control signals to the pressure regulators of the test system and the injection pump of the Common Rail system to check their operability (volumetric capacity, maximum pressure). The CP-Tester device is structurally designed as a prefix, to a sensor, a rail pressure regulator (s) and a pump pressure regulator (s) using special adapter cables. VDO OPEN SYSTEM