mczajka Posted November 2, 2015 at 12:54 PM Report Share Posted November 2, 2015 at 12:54 PM When I'm in EV mode, and I'm braking, and at the same time driving over a bridge seam or bump in the road, the car has a tendency to lurch forward. Is this the traction control kicking in? It's typically in stop and go traffic when I am going 20-30 mph (not fast). It's a little scary. I hope a car is never right in front of me. It makes me now coast over these spots and not brake right on them. My Spark EV doesn't do this. Quote Link to comment Share on other sites More sharing options...
Russael Posted November 2, 2015 at 01:29 PM Report Share Posted November 2, 2015 at 01:29 PM I think you mean anti-lock brakes. I typically won't brake over large bumps or things like railroad crossings because the car has a tendency to have anti-lock brakes kick in. They're a bit sensitive. It'll even do it if only one wheel is affected. I found that out when taking a corner a little quick and hitting a bump (such as a bump on the right side while turning right - less weight on the wheel then). It seems to do it more easily while I'm just using regen to slow down. Quote Link to comment Share on other sites More sharing options...
murphy Posted November 2, 2015 at 01:53 PM Report Share Posted November 2, 2015 at 01:53 PM If you are regen braking and one front wheel momentarily loses contact with the ground all braking action will stop until that wheel regains traction. This happens because regen braking is applied by a motor, acting as a generator, which is applied to the input shaft of the differential. The differential can only transmit force when both wheels are in contact with the ground. If you push harder on the brake pedal and activate the friction brakes there will be braking action from the wheels that are on the ground and the car will attempt to begin ABS braking for the wheel that is off of the ground. The wheel will probably be back on the ground before ABS kicks in. The same is true for one front wheel hitting an ice patch but the duration of slip will be much longer and ABS will activate. I know most of the places, where I regularly drive, that this can happen but I found a new one yesterday. Rexracer and Hybridbear 2 Quote Link to comment Share on other sites More sharing options...
mczajka Posted November 3, 2015 at 12:36 PM Author Report Share Posted November 3, 2015 at 12:36 PM Thanks for the feedback. Quote Link to comment Share on other sites More sharing options...
TX NRG Posted November 8, 2015 at 01:43 AM Report Share Posted November 8, 2015 at 01:43 AM I've experienced this when braking over a bump in both my Fusion Energi and my wife's Cmax Energi. It is a brief loss of braking which feels like you lurch forward and you have to stomp the pedal to engage the friction brakes to make up for lost time. Hopefully there is nothing close in front of you. Quote Link to comment Share on other sites More sharing options...
murphy Posted November 8, 2015 at 12:05 PM Report Share Posted November 8, 2015 at 12:05 PM The places where I encounter this are all recessed manhole covers located just before a STOP sign. The wheel ends up floating in mid air until it has time to drop onto the manhole cover. Try to avoid having either front wheel go over a depression in the road while you are braking. Quote Link to comment Share on other sites More sharing options...
meyersnole Posted November 14, 2015 at 02:54 AM Report Share Posted November 14, 2015 at 02:54 AM I think I had this happen to me today, kind of freaked me out. Almost 36,000 miles on the car first time I have felt this. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.