A method of conducting a diagnostic procedure for a braking system includes analyzing via an electronic control unit whether only a first input device is engaged or only a second input device is engaged, conducting a first diagnostic test if only the first input device is engaged, and conducting a second diagnostic test if only the second input device is engaged.

An emergency braking device including an actuator (2), a pressurizing circuit (3) supplying the actuator (2) via a control pressure and a discharge circuit (4). The discharge circuit (4) includes restrictors (13, 14) for controlling the pressure and/or flow rate of the supply fluid of the actuator (2) during a discharge of the actuator. The restrictors (13, 14) are configured to define an intermediate pressure between a low pressure level and the control pressure of the actuator (2).

An emergency braking device including an actuator (2), a pressurizing circuit (3) supplying the actuator (2) via a control pressure and a discharge circuit (4). The discharge circuit (4) includes restrictors (13, 14) for controlling the pressure and/or flow rate of the supply fluid of the actuator (2) during a discharge of the actuator. The restrictors (13, 14) are configured to define an intermediate pressure between a low pressure level and the control pressure of the actuator (2).

A method for testing a pressure-medium-operated electronic brake system of a vehicle having a valve and sensor device including a control pressure inlet, a control pressure outlet, a plurality of valves selected from electrically activated inlet valves, outlet valves, redundancy valves, and pressure valves, an actual pressure sensor for measuring an actual control pressure, a setpoint pressure sensor for measuring a setpoint control pressure, and an electronic control unit, which has a signal-conducting connection to the electrically activated valves and pressure sensors, for receiving pressure signals and actuating the electrically activated valves, includes testing the setpoint pressure sensor while the control unit is in a passive operating mode, passing the setpoint control pressure directly through to the control pressure outlet, measuring the actual pressure at the control pressure outlet using a sensor, and transmitting the measured value to the control unit for plausibility checking against the setpoint pressure measurement.

A system and method for performing a diagnostic on a hydraulic system in a vehicle while the vehicle is at a standstill. The method includes, by means of an electronic processor, moving a plunger at a constant rate, determining a position of the plunger, receiving a pressure of the hydraulic system from a pressure sensor, comparing the determined position and the measured pressure to a position versus pressure graph, and sending a diagnostic to a diagnostic indicator.

A system and method for performing a diagnostic on a hydraulic system in a vehicle while the vehicle is at a standstill. The method includes, by means of an electronic processor, moving a plunger at a constant rate, determining a position of the plunger, receiving a pressure of the hydraulic system from a pressure sensor, comparing the determined position and the measured pressure to a position versus pressure graph, and sending a diagnostic to a diagnostic indicator.

A method for initializing an electronically slip-controllable power braking system after a startup and an electronically slip-controllable power braking system. Power braking systems are equipped with a pressure generator for conveying pressure medium in a pressure medium circuit. The pressure generator includes a plunger unit made up of a plunger cylinder, a plunger piston, and a plunger work chamber enclosed by plunger cylinder and plunger piston. A characteristic, using which an actuation of the plunger piston is carried out by the motor during the initialization of the power braking system, is selected by the electronic control unit as a function of a piece of information present about the position of plunger piston at the start of the initialization and implemented by corresponding electronic activation of the motor.

To test a vehicle power braking system, a piston of a power brake pressure generator is displaced twice for a pressure build-up and in between back preferably by a longer distance. Extension of the piston travel during the second displacement is an indication of air in a cylinder of the power brake pressure generator due to an excessively low brake fluid level in a brake fluid reservoir.

Disclosed is an electric brake system. The electric brake system includes a master cylinder including first and second chambers, and first and second pistons disposed at the first and second chambers, respectively; a simulation device connected to the master cylinder and configured to provide a reaction force according to pedal effort of a brake pedal; a hydraulic pressure supply device configured to generate a hydraulic pressure by a hydraulic piston which is operated by an electrical signal that is output to correspond to displacement of the brake pedal; a hydraulic pressure control unit configured to deliver the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided at each of wheels; a first backup flow path and a second backup flow path configured to connect the master cylinder and the hydraulic pressure control unit; a first cut valve and a second cut valve configured to control delivery of a hydraulic pressure of the first and second backup flow paths; an electronic control unit (ECU); a first pressure sensor installed between the first chamber of the master cylinder and the first cut valve; and a second pressure sensor installed at the first hydraulic flow path, the second hydraulic flow path, or the hydraulic pressure control unit, wherein, in a state in which the second cut valve is closed and the outlet valve, which is connected to the second backup flow path, is opened, to discharge the hydraulic pressure in the hydraulic pressure control unit connected to the second hydraulic flow path, the ECU operates the hydraulic pressure supply device to generate a pressure in the first chamber, and when a measured value of the second pressure sensor is less than an expected value, the ECU determines that the second piston of the master cylinder is stuck.

Disclosed is an electric brake system. The electric brake system includes a master cylinder including first and second chambers, and first and second pistons disposed at the first and second chambers, respectively; a simulation device connected to the master cylinder and configured to provide a reaction force according to pedal effort of a brake pedal; a hydraulic pressure supply device configured to generate a hydraulic pressure by a hydraulic piston which is operated by an electrical signal that is output to correspond to displacement of the brake pedal; a hydraulic pressure control unit configured to deliver the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided at each of wheels; a first backup flow path and a second backup flow path configured to connect the master cylinder and the hydraulic pressure control unit; a first cut valve and a second cut valve configured to control delivery of a hydraulic pressure of the first and second backup flow paths; an electronic control unit (ECU); a first pressure sensor installed between the first chamber of the master cylinder and the first cut valve; and a second pressure sensor installed at the first hydraulic flow path, the second hydraulic flow path, or the hydraulic pressure control unit, wherein, in a state in which the second cut valve is closed and the outlet valve, which is connected to the second backup flow path, is opened, to discharge the hydraulic pressure in the hydraulic pressure control unit connected to the second hydraulic flow path, the ECU operates the hydraulic pressure supply device to generate a pressure in the first chamber, and when a measured value of the second pressure sensor is less than an expected value, the ECU determines that the second piston of the master cylinder is stuck.