Strange braking at low speed

[TheLight75]

This AM I had a new unusual experience on my way to work in my Kona. I was slowing down while approaching a stop light when the car in front of me stopped short. I was probably going about 10 mph, but when I pressed firmly on the brake, I felt a small thud and then the brakes did what I can only describe as ABS engagement in a very jerky fashion. It was jarring enough to make me wonder WTH happened. When I let off the brake and re-applied, the Kona came to a stop quietly and quickly.

The only thing I can surmise is that perhaps the braking system was transitioning from regen braking to disc braking at the precise moment I pressed hard on the pedal causing the ABS to misfire. The rest of the day, the brakes worked perfectly fine.

Has anything like this happened to anyone else? I have about 9100 miles on my Kona.

 

[KiwiME]

I've had that happen and seen other comments on this as well. I think in my case it's also due to the road surface being uneven at the approach to stops/roundabouts due to heavy vehicle braking causing ripples in the tarseal. That's also triggered the ABS in my last ICE.

 

[Mywifeskona]

I've had this happen a few times and just as recently as yesterday. It seems to me like a sudden transition from regen to brakes and the severity of it depends on how far the brake peddle is depressed.
When it happened yesterday I just happened to look at the regen lights on the dash. There were 2, maybe 3 regen bars bars lit and they went out instantly the moment that heavy braking occurred, and felt somewhat similar to what you described.
When you're lightly depressing the pedal you're actually engaging regen, not brakes. Then when you depress a little further, the car says, whoa you need brakes now, and will instantly give you the amount associated with how far your brake pedal is depressed.
Although my Kona never actually said "whoa" , that's my theory. .

 

[hobbit]

I know that transition well, as it was a common happening in the
Prius. I touched on that in the "rant about regen" post. It is much
faster in the Kona, and probably has a higher threshold of torque
variance, but it's the same mechanism.

If you can remember next time you feel it, look at the power/regen
bargraph and vary your brake pressure. It probably won't move
from about one blue bar's worth of regen. You're mostly on
hydraulics at thar point, and hopefully the car made the right
guess as to how much braking force to apply.

I'm not sure what resets to normal, but it's probably lack of
further braking events over some short time similar to the
Prius or any other modern hybrid with good integration.

In fact, as I look around the Kona I see a lot of lessons that
probably came from Toyota...

_H*