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Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca in Central California

Spark EV Braking Question

Wed Aug 14, 2019 3:02 pm

I have been noticing that when I apply the brakes in my 2016 Spark EV, slowing down seems normal until just before the car stops. Just before the car stops, I here an audible "clunk" and experience what feels like the brakes grabbing. Anyone else have this experience or can identify possible causes? My 2014 spark EV does not have this problem.

Posts: 25
Joined: Mon Jul 01, 2019 9:34 am

Re: Spark EV Braking Question

Thu Aug 15, 2019 6:19 am

It's definitely the car switching from regenerative 'braking' to actual friction pad brakes because regen can only slow the car to about 2-3 mph. Perhaps the software version in your 2014 is better than your 2016, or perhaps there was an update to the software that you're missing from the dealer?

I don't feel mine 'clunk' on my 2015 but I absolutely can tell when it shifts from regen to friction pads.

Mine feels different depending on the scenario, for instance if I was using regen only alllllll the way up to the last couple feet and barely rolling along the transition is pretty smooth. If I'm braking with medium force I feel the transition more abruptly. If I'm braking hard I feel the car using the friction brakes PLUS regen and the transition is completely unnoticeable because both brakes are engaged.

Sometimes, at low speeds as I'm using the brake pedal lightly and get down to single digit speeds, the car STILL lurches forward as I press the brake harder and harder until I have to slam on it for it to engage the friction brakes (b/c regen can't get you down to 0 mph) and then it's violent and my wife gives me a side glance and I say, "It's the stupid car's blended brake system, sorry!"

I wish they would have let the regen be attached to the accelerator pedal and friction brakes to the brake pedal only. That way I could use either one discriminately rather than the system choosing for me and often choosing wrong or harshly.

Posts: 49
Joined: Sat Aug 31, 2019 1:05 pm
Location: NJ

Re: Spark EV Braking Question

Sat Aug 31, 2019 1:53 pm

About 2-3 weeks ago, I noticed front end noises that I don't recall ever hearing before. They're fairly prominent when parking. I checked everything I could in the front end to see if something loosened up, but nothing. I contacted someone I know at the Chevy dealer and he came up with this.
PIC6122A Spark EV Noise When Braking Or Backing Up With Or Without DTC P061B Dated Jul 5, 2019.
Basically, it comes down to seeing if the HPCM T6 is up to date with programming.
Next time I get a chance, I'll have the dealer check for updates.

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Joined: Sun Jan 12, 2014 3:47 pm

Re: Spark EV Braking Question

Wed Sep 04, 2019 1:28 pm

Yep, I have the same on my 2014. Freaked me out the first few times, then I just got used to it. It's a feature!

Posts: 30
Joined: Fri Mar 17, 2017 1:57 pm
Location: Sacramento, Ca

Re: Spark EV Braking Question

Thu Sep 05, 2019 10:53 am

You might be hearing the pedestrian alert system that engages when the vehicle is traveling 18 mph or slower. It's a white noise that sorta sounds like a turbine from a long distance away, that emanates from a speaker at the front of the car.

I find it rather annoying when I have the windows down in good weather, but I do have exceptionally good hearing.
2014 Blue Spark with DCFC.

Posts: 49
Joined: Sat Aug 31, 2019 1:05 pm
Location: NJ

Re: Spark EV Braking Question

Sat Sep 07, 2019 11:46 am

This is definitely the brakes, you can hear it on both sides of the car.

Posts: 78
Joined: Mon Feb 04, 2019 10:47 am

Re: Spark EV Braking Question

Mon Sep 16, 2019 7:13 am

My brake does the slight jerk at 3mph as it transitions from regenerative to the actual brakes. I saw a video where someone had a similar issue with a clunk and it was something rolling around in his glove box that actually made the noise when he hit the brakes hard enough. It may be worth checking out?
2016 Spark EV
2017 Volt

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Joined: Mon Sep 16, 2019 2:30 pm
Location: Burnaby, BC

Re: Spark EV Braking Question

Wed Sep 18, 2019 11:31 am

The transition from regenerative braking to disc brakes is most scary when driving downhill in the rain on stock tires. The car loves to hydroplane when the disc brakes kick in. That's why I just upgraded my wheels and tires. Those low rolling resistance stock tires are not made for wet weather driving in the Pacific Northwest.

On my 2016 Spark EV I find the transition braking less noticeable when driving in L (higher regenerative braking mode). That's why I pretty much drive on L all the time except perhaps on highway driving when I want to coast a bit at higher speeds when I let off the pedal a bit.
2016 Chevy Spark EV 2LT
Konig Dial-In 15x7 ET35 4x100
Continental ExtremeContact Sport 205/50R15
JuceBox PRO 40
2018 Mitsubishi Outlander PHEV

Posts: 49
Joined: Sat Aug 31, 2019 1:05 pm
Location: NJ

Re: Spark EV Braking Question

Sat Sep 21, 2019 2:43 pm

I had the brake update done today and it feels like things are a bit smoother when slowing down. I'll have to see how it feels during my commute next.
The tech told me that besides updating the HPCM T6, the update also included updating the HPCM2 and the motor lubricating oil pump control.

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