autohold

Autohold is a driving-assistance feature that automatically maintains brake pressure after the vehicle comes to a complete stop, preventing rollback without the driver needing to keep the brake pedal depressed. It is commonly found in modern cars with electronic braking systems and automatic transmissions and is often labeled Auto Hold.

Operation and behavior: The system activates when the car is stationary and certain conditions are met, such as the transmission being in drive or park and the vehicle not moving. The brakes are kept applied by hydraulic pressure or by an electric parking brake, allowing the driver to remove the foot from the pedal. The hold continues until the driver presses the accelerator, or in some implementations until a manual release is issued. Some autohold systems include a hill-start function that temporarily maintains brake force to prevent rollback on inclines.

Relationship to related features: Autohold is distinct from a traditional parking brake, which mechanically locks the wheels when parked. It is related to hill-start assist, which helps when starting on slopes, but autohold specifically controls brake pressure during stationary periods in regular driving conditions.

Benefits and limitations: Autohold reduces driver fatigue in stop-and-go traffic and can make starts smoother after a stop. It is primarily intended for short stops and is not a substitute for the parking brake. Potential limitations include reliance on the vehicle’s electrical system; if the system fails or the battery is discharged, the held brake pressure may be released. Availability and exact behavior vary by manufacturer and model.

History and prevalence: Autohold began appearing in late-2000s and became common in mainstream passenger cars during the 2010s, especially in Europe and Asia, as part of broader electronic braking and driver-assistance suites. See also: hill-start assist, electronic parking brake.