An electric parking brake device configured to enable switching of a control mode between: a switch operation mode to lock and release electric parking brakes by operation of an electric parking brake switch; and a shift link operation mode to lock and release the electric parking brakes in conjunction with shift operation of a shift lever. The electric parking brake device has a mode selection controller to select the shift link operation mode as the control mode if the switch breakdown determiner determines that the electric parking brake switch is broken down and the brake operation determiner determines that the electric parking brakes are in the locked state.

A method for operating a brake system having a brake fluid reservoir having a first and a second reservoir chamber which are separated by a first partition wall, wherein a first filling level in the brake fluid reservoir is determined by a first sensor element, and a second filling level in the brake fluid reservoir is determined by a second sensor element, wherein the brake system is operated in a first fallback operating mode when the determined first filling level in the brake fluid reservoir falls below a first predetermined level (p.sub.1), and wherein the brake system is operated in a second fallback operating mode when the determined second filling level in the brake fluid reservoir falls below a second predetermined level (p.sub.2), wherein the second level (p.sub.2) is lower than the first level (p.sub.1), and to a brake system.

A testing method includes the steps of: (1) providing a negative pressure generator; (2) generating a negative pressure in a fluid passageway and a chamber which are in fluid communication with a guiding section of a fluid reservoir wherein a second sensing element is affixed to a guiding section of the fluid reservoir; (3) transferring a fluid flow stream from the guiding section to the chamber via the fluid passageway and drawing a float having a first sensing element from an upper position to a lower position within the guiding section; (4) generating a signal via the first and second sensing elements as the float moves relative to the second sensing element within the guiding section; and (5) transmitting a signal to at least one of a control unit or a graphical user display.

Disclosed herein are a brake fluid pressure sensor validity determination device and a determination method thereof. According to an embodiment of the present disclosure, the brake fluid pressure sensor validity determination device and the determination method thereof includes an inputter configured to receive a brake fluid pressure sensor value sensed by a brake fluid pressure sensor and receive a motor position sensor value sensed by a motor position sensor, an estimator configured to estimate a brake fluid pressure value on the basis of the motor position sensor value when the motor position sensor has not failed; and a determiner configured to determine whether the brake fluid pressure sensor has failed, determine whether the motor position sensor has failed when the brake fluid pressure sensor has not failed, and determine a validity of the brake fluid pressure sensor by comparing the estimated brake fluid pressure value with a brake fluid pressure sensor value.

A brake system control module for use in a brake system is provided. The brake system control module includes a reservoir tank having a brake fluid level sensor. The brake system control module automatically determines if the brake fluid level sensor detects a low fluid level in the reservoir tank and monitors a value of sensors to determine if the value of the sensors is less than or greater than evac and fill start and stop thresholds. The brake system control module further manages an evacuation and a filling of the brake system based on the value of the sensors.

A brake system comprises a first electrohydraulic open-loop and closed-loop control unit. The first electrohydraulic control unit comprises a master brake cylinder actuatable by a brake pedal; a first electrically controllable pressure-providing device; and an electrically controllable pressure-modulating device sets wheel-specific brake pressures for the wheel brakes. The electrically controllable pressure-modulating device has at least one electrically actuatable inlet valve for each wheel brake. A first pressure-medium reservoir for supplying the first electrohydraulic control unit with pressure medium is arranged on the first electrohydraulic control unit. The brake system also comprises a second electrohydraulic open-loop and closed-loop control unit, which comprises a second electrically controllable pressure-providing device for actuating at least some of the wheel brakes and electrically actuatable valves. A second pressure-medium reservoir for supplying the second electrohydraulic control unit with pressure medium is provided, the second pressure-medium reservoir being arranged on the second electrohydraulic control unit.

A reservoir tank includes a reservoir body defining a storage chamber for an operating fluid; and a float guide in the storage chamber. The float guide forms a float chamber on the inner side. The reservoir tank further includes a fluid level detection device that has a float moving up and down in the float chamber in accordance with fluctuations of a fluid level, and has a detector detecting when the float is below predetermined position. The reservoir tank is provided with a slit in the float guide. The slit is in communication with the storage chamber and the float chamber. An operating fluid passage is provided on an inner face of the float guide which is continuous with the slit, which is in communication with the slit and the float chamber.

A method for operating a hydraulic brake system for a motor vehicle that includes a hydraulic brake system with a hydraulic unit, a brake fluid reservoir and hydraulically actuatable wheel brakes, wherein the hydraulic unit has a main pressure source which can be actuated via a brake pedal, an additional pressure source fluidically separate from the main pressure source, and control valves by which the main pressure source and the additional pressure source on one side and the wheel brakes on the other side are connected together, wherein in the brake fluid reservoir, multiple at least partially mutually separate reservoir chambers are provided for supplying the main pressure source and the additional pressure source with a brake fluid, wherein the method comprises detection of a fill level of the brake fluid in the brake fluid reservoir by a measurement assembly, wherein the detection of the fill level takes place in analog fashion.

A method for controlling a brake system in the case of leaks is provided. The brake system has a mechanically actuable master brake cylinder, which is connected to a first partial reservoir of a brake fluid vessel, and has an electric linear actuator, which is connected to a second partial reservoir of the brake fluid vessel. The master brake cylinder and the linear actuator are connected via an electrically closable circuit isolating valve. In order to protect the brake fluid, in the event of a leak during a transition to a standby state, the linear actuator is activated to take a brake fluid volume out of the first partial reservoir via the open circuit isolating valve and to displace it into the second partial reservoir.

A vehicle braking system including a brake pedal in communication with a wheel brake, a brake actuation system, a braking system controller, an on-board driver communication system, and a controller is described. Parameters associated with a braking request, a brake actuation command and vehicle operation are monitored during each braking event, and segmented the into parameters associated with a static portion of the braking event and parameters associated with a dynamic portion of each braking event, evaluate the parameters associated with the static portion of the braking event and evaluate the parameters associated with the dynamic portion of the braking event, and assess a state of health of the braking system based upon the evaluation of the parameters. The assessment of the state of health of the braking system is communicated to a vehicle driver via the on-board driver communication system.