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Hello, I just got into an accident with my 2014 volt. I was driving on a local road over a ditch, and a sign showed up on the dashboard, "low traction". That is when the brakes stopped responding, the volt apparently sped up and reared the car in front.

I thought I had this "low traction" problem a couple of time before, so wonder if anyone had a similar problem. My car is the dealership and I am trying to get them looking into this.
 

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I doubt that the car actually sped up. It can feel like that way for a moment when the regenerative braking cuts out. It then takes more pedal force. I'm pretty sure the regeneration cut out and the ABS was trying to address wheel lock up. Was the car in Low?

Let us know what the mechanics find.
 

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This is a common complaint when braking the car on a rough surface that activates the ABS. ABS will cancel out all regen braking, so the sudden loss of regen feels like the car is speeding up. Drive in D and be prepared to press the brake pedal farther/harder to engage more friction braking over rough surfaces in case this happens again.
 

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Yes, the car doesn't speed up/accelerate on its own but simply stops regen braking when traction is lost. It may feel a bit weird if you're not used to it.

You can even easily simulate this: while driving downhill, let off the gas pedal to regen and then switch to N gear. No regen anymore. Of course the car will then speed up but that's gravity pulling you, it's not accelerating on its own.
 

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I've had this numerous times and it freaks me out every time. Happens pretty much every time I'm braking even moderately hard and hit a bump while on the brakes. It does feel like it's speeding up, but it's not. Several times I've come with in what feels like inches from rear ending someone, but that's usually due to me following too closely to begin with.

Sorry for your accident, but I'm glad it's not just my Volt that does this.
 

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This has never happened to me in 60K miles of driving, and I live and work in areas with many RR crossings, where something like this is likely to happen. But I keep the transmission in D and always try to brake early and gradually, keeping the efficiency ball green.
 

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Yeah, this is weird. I drive in L all the time and go over RR crossings all the time--never experienced this.
 

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It happens to me every once and a while. You have to hit the brakes relatively hard while going over a sizable bump. Not like panic stop hard, but probably near 50%.
The other time it can happen is on ice. Then you don't have to hit the brakes quite as hard.
 

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Now that I think about it, I have a habit of taking my foot off the brake when crossing a bump so that the front suspension is not compressed and is able to take up the shock with its full travel. I guess that would prevent ABS activation and therefore this problem. Also, I have only rarely driven on snow or ice with this car. So that may be why I have never experienced it.
 

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My car is the dealership and I am trying to get them looking into this.
Nothing to look into I think. As the posts above point out, loss of regen makes it feel like the car speeds up, but it's not. This affect can occur whenever traction is lost between the wheel and the car. Avoid Low if this concerns you.

I had it happen once. It is a weird feeling.
 

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Nothing to look into I think. As the posts above point out, loss of regen makes it feel like the car speeds up, but it's not. This affect can occur whenever traction is lost between the wheel and the car. Avoid Low if this concerns you.

I had it happen once. It is a weird feeling.
Probably right.

I think there's nothing really wrong and it's just a consequence of ABS. I don't think this behavior is unique to the Volt. I do feel that getting used to driving around in Low and using less brake pedal effort might make it unnerving when traction is lost and ABS acts to avoid wheel lock. For some avoiding Low most times might be a good idea. IIRC there are situations that the manual recommends not using Low.
 

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Probably right.

I think there's nothing really wrong and it's just a consequence of ABS. I don't think this behavior is unique to the Volt. I do feel that getting used to driving around in Low and using less brake pedal effort might make it unnerving when traction is lost and ABS acts to avoid wheel lock. For some avoiding Low most times might be a good idea. IIRC there are situations that the manual recommends not using Low.
There is no difference between using L or D in this situation. You are still utilizing regen braking either way.
Personally I think it's more a fact of the regen braking cutting out than the ABS. ABS pulses the brakes so fast that it would still slow you down at nearly the same rate. What is happening here is the car takes a half a second to replace the regen braking with the friction brakes.
 

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While technically not accelerating when this happens, the fact is, you are also suddenly not decelerating for a moment. When the regen kicks out and before the friction brakes grab, you have a period of coasting. This brief period of coasting will increase your stopping distance slightly and when attempting to avoid an accident, the distance travelled during coasting matters.
 

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A reminder to all of those that use L for enhanced regenerative braking.
1. Regen braking (whether D or L, or brake pedal regulated) operates on only two wheels. You'll not get full stopping capability with regen. Fortunately most of the time the friction coefficient of the two drive wheels is sufficient for gradual slowing. In low traction situations shift to N and let the friction brakes spread the slowing and stopping demand to all four tires.
2. Regen braking (D or L) does not illuminate the brake lights. The enhanced deceleration rate possible when in L might catch the operator behind you unaware that you are slowing more rapidly than a coast-down.
 
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