Well apparently this is a normal operation of the electric motor engaging (or releasing) during the process of braking at low speeds or at least according to the Service Adviser at the Rydell Chevrolet dealership in Northridge, CA. I dropped the car off this morning because of this issue and due to the fact the car was pulling to the left when braking as well (hence my concern of a warped rotor, etc.) but although the tire pressure status showed a consistent reading of 33 to 34 psi on all tires, the front driver's side tire was nearly six pounds low. So for future reference, always consult a good tire pressure gauge measurement first if you experience this type of condition. Oops!markcmann wrote:Have any of you Spark EV owners noticed an issue with braking to a complete stop (gradual not slamming on the brakes) and felt a pulse (skipping) or almost like the rotor is warped? I have a little over 400 miles on the car and have been very careful in breaking in the brakes by not slamming on the brakes and using the 'L' mode more often to take advantage of the regen but the last day or two I've noticed this and wondered if it normal or not? I might need to take it in for service to check into it?
Sounds very similar to what I have been experiencing. It's not entirely clear to me if this has been happening since I took ownership of the car or if once I noticed it I'm hyper-sensitive to it now? But according to the dealership's service adviser, this is normal and they verified it by duplicating the issue with another Spark EV that was on the lot. I do notice it more when backing up (in reverse) and stopping to change the gear selector to 'D' (drive) and I do notice it more when coasting (or creeping) and then applying the brakes; not when pressing the brakes from normal speeds like if traffic stops or slows in front of you. So I'm a little glad someone else has the same experience as I didn't want to have a problem with my new car.wutangmo15 wrote:I may have experienced a similar issue yesterday. I was coming to a stop coming out of a parking lot. The road was clear so I did not come to a complete stop and felt a thump and heard a kind of bang noise. It did seem like the motor was disengaging and then re-engaging when I hit the accelerator pedal.
I haven't been able to reproduce the issue and everything appears to be normal.
I've driven my girlfriends Spark EV a few days, after she noticed similar braking concerns to yours, and I only felt a pulsing/pumping sensation as the car powered-up. I've never noticed that feeling while coming to a complete stop. (Though I was using L quite a bit to modulate & control braking before stops) I do think it can be the nature of some regenerative brakes to be a bit grabby right before coming to a stop. We also asked Chevy, and they responded that it's normal for the car. Not that it's any consolation for someone who finds it to be an annoyance.The front brakes include an electro-hydraulic regenerative brake system that captures braking energy...
Thanks for the link. Like I stated in an earlier post, I think I am just hypersensitive to this behavior now and will just have to learn to deal with it...at least for the next 35 months.CopperRoad wrote:The car apparently uses an electro-hydraulic system for the front brakes.
The below was taken from a Chevy media kit -> http://media.gm.com/content/media/us/en ... /2014.html