Patent ID: 8301331

Claim:
A method for the calibration or diagnosis of a motor vehicle brake system having an operating pump operating in a pulsed fashion during which a pulse period for applying voltage to the operating pump and an interpulse period for not applying voltage to the operating pump are alternated, the method comprising: repeatedly determining, by a reference processor, during operation of a reference pump separate from the motor vehicle, under defined stipulations, at least a voltage (U RP off ) generated by the reference pump during the interpulse period and representing the electromotive force of the reference pump; deriving, by the reference processor, a statistical characteristic variable ( U RP Off ) from the voltage (U RP off ); determining, by an operating processor, during operation of the operating pump in the motor vehicle, a voltage (U BP Off ) generated by the operating pump during the interpulse period and representing the electromotive force of the operating pump under corresponding stipulations; deriving, by the operating processor, a corresponding statistical characteristic variable ( U BP Off ) from the voltage (U BP Off ); calculating, by the operating processor, at least one ratio as a measure of the deviation of the operating behavior of the operating pump from the operating behavior of the reference pump from the characteristic variable ( U RP Off ) and the characteristic variable ( U BP Off ); and determining, by the operating processor, if the operating pump in the motor vehicle is defective by comparing the at least one ratio to a tolerance range.