An Electronic Parking Brake (EPB), also known as an electric parking brake or electric park brake, is an electronically controlled parking brake that is activated by the driver with a button or switch on the dashboard or console. When activated, an electronic control unit (ECU) signals the brake pads to be electrically applied to the rear wheels. EPB systems can be considered a subset of Brake-by-wire technology. EPB systems provide other functions like automatic release of the park brakes when the driver presses the accelerator or slips the clutch, and re-clamping using additional force on detection of vehicle motion.
EPB systems were first installed in the 2001 BMW 7 Series (E65) and have since appeared in a number of vehicles. EPB systems can be either cable puller systems or caliper integrated systems. The EPB is applied automatically if the Auto Hold button is on when the engine is turned off. However, if the EPB switch is pressed until the engine is turned off, the EPB will not be applied.
EPB systems have several advantages over traditional cable-actuated parking brakes, including:
- Space-saving: The EPB system allows for more space in the car.
- Automatic release: EPB systems can automatically release the park brakes when the driver presses the accelerator or slips the clutch.
- Re-clamping: EPB systems can re-clamp using additional force on detection of vehicle motion.
Despite being a straightforward and effective design, cable-actuated parking brakes had several drawbacks. First, a driver could inadvertently leave the parking brake partially engaged.
