What to Do When Hill Start Assist Malfunctions?
2 Answers
Hill Start Assist has specific activation conditions. When a malfunction occurs, first check whether the vehicle and road conditions meet the following criteria: The handbrake is not engaged; for manual transmission models, the gear lever should be in the neutral position, while for automatic transmission models, the gear lever should be in a non-P position. The vehicle must be stationary, and the accelerator pedal should not be pressed. If the conditions are met but the Hill Start Assist still malfunctions, drive the vehicle to a 4S shop or repair shop for inspection. More details are as follows: 1. The system cannot always keep the vehicle stationary on a slope under all conditions. For instance, on slippery surfaces like wet or icy roads, the vehicle may slide due to insufficient tire grip. 2. The Hill Start Assist system is not entirely equivalent to the handbrake (foot brake or electronic handbrake). It is only suitable for general hill starts; for prolonged parking, the handbrake must still be engaged. 3. Auto Hold, based on the electronic handbrake, maintains braking continuously on both flat and sloped roads once activated, until the sensor detects the accelerator pedal being pressed. 4. In contrast, Hill Start Assist relies on the ESP hardware unit and only activates when sensors detect the vehicle is on a slope. It maintains braking briefly before automatically releasing, regardless of the accelerator pedal.
It's quite annoying when the hill start assist suddenly stops working. I’d like to share some experience. Common causes are mostly sensor failures, such as dirty or debris-covered wheel speed or tilt sensors, or system software glitches. I’ve encountered this a few times—first, try the simplest solution: restart the engine by turning the car off and on again to see if the function resumes. If that doesn’t work, check the owner’s manual for the location of the related fuse to see if it’s blown. Also, ensure the brake system is functioning properly, as hill start assist relies on the ABS module—checking if the brake lights are working is also important. You can DIY by cleaning the sensors near the wheels with a damp cloth. If multiple restarts don’t help, it’s best to visit a professional repair shop for a diagnostic scan to avoid the risk of rolling back on a slope and causing an accident.
