Brakes grab and release when coasting from 26-18 mph

brakes

#1

My 2016 Chevy Sonic seems like someone is tapping the brakes on and off from when it hits 26 mph down to about 18 mph and then it stops. It goes in and out about 5-6 times while coasting. I think I feel it a little even when I’m braking throughout those speeds as well. Any ideas what could be causing that to happen?

P.S. The ABS light came on when driving it earlier today for a little while and then turned off. Thinking it could possibly be related.

P.S.S I just drove it and I noticed that the RPM when coasting jumps from 1,000 to about 1,200 when the “braking” feeling starts and goes back down when it feels like it’s being released.


#2

2 year old car under warranty? Might wanna take it back to the Chevy dealer and let them give it a look.


#3

The only warranty that is left on it would be the power train warranty currently.


#4

Likely a stability control problem. A bad sensor or a weak battery can confuse the stability control into thinking you are ready to spin out so it applies the brakes. A tech needs to ride with you with a scanner connected to the car’s ABS system to read what is happening when it occurs - as well as read out any error codes the systems have stored.

Modern, computer age cars are easy to diagnose if you have the tools and the smarts to interpret the data.


#5

do you have tires of the same model/size in from and in rear?

if we assume this is a stability control, having tires of different sizes may be one of contributing factors, at least theoretically?


#6

Yes, could be. Wheel speed sensors don’t like different readings.


#7

Wow! 36 month 36,000 mile warranty on a 2016! I checked and it was the same for 2018 GM vehicles! Warranty is a huge selling point indicating the manufacturer’s confidence in their product. My 2010 Kia and it’s cousin Hyundai have 60 month/60,000 mile standard warranties and 10 year/100,000 mile powertrain. I guess GM is counting on being bailed out as many times as needed.


#8

Sounds like the vehicle is down shifting, completely normal.

The ABS light is not normal but I doubt that the brakes are grabbing.

Toyota’s basic warranty is also 3 years/36,000 miles. Lexus is 4 years/50,000 miles, Kia must be the better car.


#9

Kia is only the potential customer perceived better car with the better warranty.


#10

I’m guessing it’s a transmission problem, and these are rough shifts in gears.