By now you should already know that the 2012 Chevy Sonic will debut with a segment-exclusive feature called Hill Hold Assist, which prevents a Sonic with a real manual transmission from rolling backward or forward when starting on a hill. In the video that follows, Sonic lead development engineer John Buttermore explains how Hill Hold Assist works.
For starters, Hill Hold Assist uses the Sonic’s chassis control system (in this case, the electronic brake modulator) to hold the vehicle from rolling backwards when on a hill facing up) or forwards (when on a hill facing down). This chassis control system is comprised of three sensors detecting yaw, pitch, and steering angle that interact with the (standard on all models) Stability Control and ABS systems of the car.
The pitch sensor can detect whether the Sonic’s nose is pointing up (on a five percent grade) and, upon being thrown into first gear and sensing the release of the brake pedal, will continue to apply the brakes for two seconds. The same holds true when the Sonic’s nose is pointing down (also on a five percent grade) and the driver shifts into reverse.
At the end of the day, Hill Hold Assist holds the Sonic in place for two second after the driver releases the brake pedal, allowing for the proper blend of clutch and gas for a smooth takeoff. What’s more, the brake light continues to stay on when the driver releases the brake pedal and Hill Hold Assist is activated, providing the right communication to the driver behind the Sonic. The GM Authority crew finds this implementation nothing short of ingenious, but we wonder whether the same tech will make its way to the Sonic’s twin — the Aveo — elsewhere in the world. Now, without further ado, let’s let John show you how it’s done.
Comments
Wow, this is a really good idea. It looks like the Sonic will be a very popular car and this feature will be great for when I teach my daughter how to drive stick shift. Hills have always been troubles where I live so might help me as well :p. Lots of discussion about the Chevy Sonic over at http://www.sonicownersforum.com – looks like Chevy will have a real winning car on their hands!! Can’t wait for it to come out next month…
No, this is a horrible idea, at least as done by GM. Why would the brakes hold for two seconds? Why would it not release as soon as you depress the gas? This is stupid AND dangerous as you kill your engine fighting the (idiotic) brakes, on a bad hill, with cars rear ending you.
Can you give an indication of where to look for a defect if the hill hold assist doesn’t work anymore.
@Serge I’m not aware of any such indicators… but I guess if the car isn’t holding on a hill, then that should be some cause for concern. Are you experiencing any issues with hill hold assist?
Yes, we are experiencing a problem with the hill hold assist; it doesn’t work since a couple of months; and the dealer hasn’t found the solution yet, this device being so new to them. Of course, the fact that the hill hold assist doesn’t work properly doesn’t cause a major concern because both my wife and I are used to using a manual transmission; however, when it works properly, it’s pretty handy.
Straight from the owners manual: The brakes will release if the accelerator pedal is pushed within the 2 second window.
My hillside assist is not working properly for the past 2 weeks. My car has 40,000 miles on it and it is 2 years old, so my basic bumper to bumper warranty is expired. Will my drivetrain warranty which is still good, cover the hillside assist repair?