What does the HAC hill-start assist system mean?
1 Answers
Hill-start Assist Control (HAC) is a function derived from the ESP system. It allows the vehicle to maintain braking for a few seconds after the driver's right foot leaves the brake pedal when starting on a slope without using the handbrake. This enables the driver to easily move their foot from the brake pedal to the accelerator pedal, preventing rollback accidents and avoiding panic situations. Additional information: 1. Conditions for hill-start assist system activation: The gearshift lever is in any position other than P (for automatic transmission models); the accelerator pedal is not depressed; the vehicle is stationary; the parking brake (handbrake or foot brake) is not engaged. 2. Principle of HAC: When starting on a slope, the moment the driver's foot leaves the brake pedal to press the accelerator, the HAC system automatically maintains brake hydraulic pressure for 2-3 seconds, equivalent to the brake still being pressed, so the vehicle won't roll back. When the accelerator is pressed, HAC's brake control automatically ends, and it doesn't release all braking force at once but gradually reduces it, allowing the vehicle to start smoothly with the accelerator. If the accelerator isn't pressed, HAC's automatic brake control will also end after 2-3 seconds, so the driver can press the accelerator at a relaxed pace.
