The C7/7.5 platform has a lot of onboard driver assistance technology, including automatic parking brake engagement and release. At least it does on the European models with Hold Assist (2nd button immediately below the handbrake button)
If I come to a halt in my S7 and press and hold the footbrake for a second or two, the parking brake is engaged and l get a 'handbrake on light' on the dashboard that you can't miss.
If all doors are closed and the drivers seatbelt is on, the electronic parking brake auto releases as soon as l press the accelerator.
If l attempt to drive off with the parking brake engaged (no seatbelt on - coming out of my garage for example) the car absolutely does NOT move, and I get a warning on the DIS screen.
Finally, if the car applies emergency braking (or ACC controlled braking) for whatever reason, the brake lights are immediately activated.
In order to be in launch mode, as well as actually activating launch control, you need to be standing on the brakes while flooring the accelerator to high RPM.
I've watched the video a couple of times, including frame by frame, and observe the following.
1. The car is not launched - Launch control (assuming properly selected) requires you to stand on the brake pedal while flooring the accelerator, in effect using both feet. You then lift off on the brake and off you go. It's not a natural movement and takes a little practice to get right. In this instance the driver is on the brake (brake light is on) however he is not on the accelerator. You can hear the engine gun as soon as the brake lights go out. At this point he's simply driving it like a regular car, albeit he's driving it fast. However he's flooring the accelerator with stability control switched off (assuming set for launch control)
2. When the wheels lock up the brake lights are not on. You can just see the brake lights illuminate after the lock up actually happens. I think this is the drivers natural reaction to what occurred. He hit the brake.
3. The car haunching down at the start of the acceleration is normal dynamic forces at work when you floor the accelerator.
4. There is no evidence that the parking brake is engaged. He lifts off the footbrake and immeadiately accelerates with no hesitation. You cannot hear the parking brake disengage.
Let's give the driver the benefit of the doubt.
There is no reason whatsoever for him to take his hand off the wheel (in the midst of a high speed run) and apply the electronic parking brake. The brake lights do not come on until after the lock up occurs. Even if the driver decided to abort the drive, manually standing on the brakes would have initiated the ABS system, preventing the full lockup of the wheels. The electronic parking brake is normally only applied to the rear wheels, however if the car is travelling over a certain MPH, manually pulling the parking brake switch, and holding it in the pulled position, will apply emergency braking to all four wheels. It's not clear from the video if all four wheels locked, or just the rear. But for emergency braking to continue to be applied, you must keep pulling on the switch. If you release the parking brake switch (or accelerate) emergency braking is disengaged.
Pulling and continuing to pull on the parking brake switch in order to initiate emergency braking is absolutely not something you can do by accident.
I still say you should engage your dealer for advice, as this simply doesn't look right.
You (or someone) should also try and duplicate the fault.
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Originally Posted by Don Draper
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