Patent ID: 8538663

Claim:
A method for adapting a performance of a fuel prefeed pump of a motor vehicle which has a common rail injection system, an internal combustion engine, the common rail injection system including the fuel prefeed pump and a high-pressure fuel pump arranged downstream of the fuel prefeed pump and configured to deliver fuel to a common rail, the method comprising: after the ignition is switched on and before the internal combustion engine is started, determining and storing adaptation values which are assigned to the fuel prefeed pump and describe its individual performance by: for each of a plurality of different performance values: communicating control signals to actuate the fuel prefeed pump according to the performance value to cause the fuel prefeed pump to deliver fuel from a fuel tank to the rail via the high-pressure fuel pump, such that the fuel pressure in the rail reaches a prefeed pressure created by the fuel prefeed pump, and measuring the fuel pressure in the rail using a pressure sensor, and determining and storing adaption values based on the measured fuel pressures corresponding to the different performance values for the fuel prefeed pump, and during normal operation of the common rail injection system after the internal combustion engine is started, determining an actuating signal for the prefeed pump using the adaptation values to supply fuel to the high-pressure fuel pump at a desired pressure.