markcmann
Posts: 145
Joined: Sun Jun 23, 2013 9:31 pm
Location: Southern California

Spark EV Braking Issue

Sat Jul 13, 2013 2:48 pm

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?

drivefast
Posts: 39
Joined: Wed Jul 10, 2013 8:48 pm

Re: Spark EV Braking Issue

Sun Jul 14, 2013 6:48 am

i had that "alright, you should stop now" feeling, with all my brake pedal down, on my test drive. for some reason i'm expecting to feel it again sometime. i wasnt in L, i was in normal drive. it felt like some sort of a flywheel was still spinning and pushing the car. i want to have it happen again and investigate further.

markcmann
Posts: 145
Joined: Sun Jun 23, 2013 9:31 pm
Location: Southern California

Re: Spark EV Braking Issue

Mon Jul 15, 2013 3:51 pm

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?
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! :oops:

wutangmo15
Posts: 20
Joined: Mon Jul 08, 2013 10:21 am
Location: Bay Area

Re: Spark EV Braking Issue

Wed Jul 17, 2013 12:44 pm

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.

markcmann
Posts: 145
Joined: Sun Jun 23, 2013 9:31 pm
Location: Southern California

Re: Spark EV Braking Issue

Wed Jul 17, 2013 1:27 pm

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.
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. :)

markcmann
Posts: 145
Joined: Sun Jun 23, 2013 9:31 pm
Location: Southern California

Re: Spark EV Braking Issue

Wed Jul 31, 2013 9:02 pm

I hate to bring this up again but have any of you Spark EV owners noticed the odd computer modulated braking issue which feels like a pulsing, stuttering or skipping sensation at very low speeds when lightly applying brake pressure to the pedal right before coming to a complete stop? It's a bit unsettling and feels like something is wrong. I can duplicate the issue in reverse, drive and low gear and it's driving me crazy.

According to the Chevrolet Service Advisor, this is "normal" but it really seems like something is ether adjusted wrong or the computer modulation is calibrated incorrectly. It's my understanding the braking system on the Spark EV is not the same as a conventional automobile and is basically a "brake by wire" system as opposed to a traditional mechanical hydraulic system. Anyone???

CopperRoad
Posts: 12
Joined: Thu Jul 25, 2013 4:16 pm

Re: Spark EV Braking Issue

Thu Aug 01, 2013 1:34 pm

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
The front brakes include an electro-hydraulic regenerative brake system that captures braking energy...
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.

As an aside, I must say as a Leaf owner - the Spark EV is a supremely fun car to drive.

markcmann
Posts: 145
Joined: Sun Jun 23, 2013 9:31 pm
Location: Southern California

Re: Spark EV Braking Issue

Thu Aug 01, 2013 4:19 pm

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
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. ;)


ezjam
Posts: 10
Joined: Sun May 11, 2014 9:25 pm

Re: Spark EV Braking Issue

Tue Jan 06, 2015 2:50 pm

This is also happening to me and I find it extremely annoying. I took my EV in to get it checked for this and they were unable to reproduce with my car or with a new car from lot. Hence they concluded this was "normal." WTF? They cannot reproduce therefore it's normal!

My theory is this, if this ALWAYS happened, then yes, it could be normal. However, because it is non-deterministic, the only conclusion is that something is not properly calibrated. Maybe it only happens when decelerating at the threshold between switching between electrical and mechanical braking, in which case a hysteresis loop may solve the problem. I don't know, all I know is that I find it EXTREMELY annoying.

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