Abstract: The invention provides a method of detecting a defective condition on a pressure switch arrangement which at least assumes a defective condition on the said pressure switch assembly whenever a signal arrives at an input of an electronic computing unit which cannot be associated either to the opened or to the closed condition of the pressure switch. Moreover, a defective condition on the pressure switch arrangement mounted in the brake system of a vehicle is assumed, once the pressure switch signal refers to an actuated brake although the vehicle is significantly accelerated. Conversely, a defective condition is also assumed if the vehicle significantly decelerates although the pressure switch signal refers to a lack of brake pressure. Also, an appropriate pressure switch arrangement is provided which, with the pressure switch closed, generates a rectangular signal and, with the pressure switch opened, generates a high level on the input II of an electronic computing unit.

Abstract: The present invention discloses a brake system with electronic brake force distribution which includes additional criteria of deactivation of the electronic brake force distribution. Deactivation of the electronic brake force distribution is intended to occur, on the one hand, if a pressure increase phase lasts longer than a defined time (50). On the other hand, another criterion of deactivation (60) is deceleration-responsive, and an additional check is made whether or not braking is pedal operated (62).

Abstract: In a brake system with electronic brake force distribution, the electronic brake force distribution is deactivated as soon as the maximum vehicle deceleration achieved during electronic control falls below by a given factor between 0 and 1, for example, two thirds. The purpose is that an early exit from the electronic brake force distribution is effected even if the brake light switch is defective, with the result that unnecessary valve actuations and the risk of underbraking are prevented. The present invention is applicable to brake systems where the criteria for the activation of the electronic brake force distribution are independent of a brake light switch signal, and to other brake systems if there is a defect in the brake light switch. The present invention makes it possible to sense in good time that the driver has taken his/her foot off the brake pedal or no longer desires heavy deceleration.

Abstract: A method of monitoring a brake system which is equipped with anti-lock control (ABS) and a system for electronic control of brake force distribution (EBV). The system includes two brake circuits in a black/white brake circuit split-up, the EBV function or control is principally released only when the vehicle deceleration exceeds a predetermined limit value (GWN). To identify a front-axle brake circuit failure, acceleration criteria, i.e., criteria responsive to the acceleration behavior of the vehicle wheels, are predetermined and monitored. Further, slip range monitoring in conjunction with acceleration range monitoring is performed.

Abstract: A circuit for a brake system with pressure fluid distribution, anti-lock control, and traction slip control. The circuit includes circuits to monitor the brake system and to change over or disconnect the control in response to defects and/or the respective control situation or driving situation. Upon failure of any one of the sensors which sense wheel rotation behavior or one sensor per axle or in the presence of an incorrect sensor signal, the vehicle reference speed is produced on basis of the intact sensors, and an electronic brake force distribution control function is still possible, however, an anti-lock control or a traction slip control is prevented. When the defective sensor is a rear-wheel sensor, both rear wheels are controlled synchronously.