"Check regenerative brakes" - Kona 2021

Eugene, OR: We have had a VERY similar story! In Sept. of 2021, I began to intermittently get the "Check regenerative brakes" error message in our 2020 Kona EV Limited, and after turning the car on and off, thinking it might simply be a software issue, I did call the dealer and took it in. As Montaigne states, they could not find anything wrong, so said to let them know if it pops up again, but they were able to make it go off. It occurred 2-3 other times, almost always when I first turned the car on, once with a co-worker with me doing a delivery (we own a bird seed/supply store). I simply turned the car off, waited a few minutes, then turned it on and all good.

But, yesterday, I tried my usual default action and no go. The light did not turn off, braking was still normal, but I was suspicious now. I called the dealer as I was heading that direction because it was already almost 4 pm on a Friday. I NEED a car due to a disabled husband, so I can't simply be without a car; too dangerous in case he has an issue.

They go it in to a tech and we waited, as we were all there, husband, puppy, me, dog crate, stuff in car, yada yada! Dog did not like the showroom, too open and weird, so he was stressed, husband was stressed, etc. They DID find that we need a new brake module as well, and, at first, because all of their 10 loaner cars are out with other customers waiting on parts deliveries, they couldn't get us a car to drive home, with all of the entire family, etc. Now I was stressed! But, after trying to call Enterprise for a rental and they were closed and not answering their phones (it was now 5pm) we looked worried enough the service guy said he'd see what he could do.

First of all, the folks there have been very interested in helping customers out, they've been very kind and willing to look into this, but were as baffled as we were each time, because he computer diagnostics were not telling them what they needed to know. The glitch I think is in the diagnostics...

So, he came back and asked if we would be willing to accept a loaner of a different brand of car, as they also sell Volvos there. I said as long as it's safe, has wheels, can get us where we need to go, I'm fine...does have to fit the dog crate, though, as he's a puppy and not good in the car without the crate. So, we now are borrowing a 2022 Volvo XC 40 and although it's an ICE car, it's got lots of bells ad whistles so I joked with them, telling them they were sneaky and trying to spoil us! HE did say it was a band new car and was for sale! (There is an EV version, though... hmmm)

So, supposedly Monday a customer will get to take their car home again, as their parts are due in for the 3rd time (they keep shipping them so poorly packaged that they are damaged upon arrival!) At that tiem, assuming the parts come in okay, we are supposed to bring the Volvo back and get an official loaner car. But, meanwhile, this is fun to drive, well, not fun, but cushy!

I'll post back to keep folks updated. But, it does sound as if they need an earlier warning system for the regenerative brakes going bad, before they really are at the end of their life!

 

I had a recall #01D102 (R0178) performed on my 2020 Kona Preferred on in Mar. 2021. The problem: "Vehicle equipped with Integrated Electronic Brake (IEB) system that might significantly reduce braking performance upon detection of an abnormal sensor signal. Reduced braking power could extend the vehicle stopping distance." The procedure was an IEB unit software update.
In June of this year the "Check regenerative brake" warning light came on and the parking brake light came on at the same time at random intervals when driving. The regenerative brakes were operating ok and the parking brake was in fact not on. I took the vehicle in to Hyundai Victoria but the mech. could find no reason for this so I was sent away and told to monitor.
This kept happening randomly and in July, twice when coming to a stop using the hyd. brakes and with regen. braking in position #2, there was a kickback on the brake pedal and the "Check regenerative brake" light came on at the same time. The veh. did stop ok. I took the veh. in to Hyundai again and they still couldn't find a reason for this happening. After leaving the dealership the warning came on again so I turned around and went back so the mech. could plug his reader in while the warning was displayed. I was told they should be able to find the cause now and they would call and let me know what they found but no one called.
About a week later when the brake pedal was depressed to come to a stop the pedal was hard and unresponsive and all the warning lights and buzzers on the dash came on at the same time. The brake pedal was pressed again and harder but still would not stop the veh. The third time the pedal was depressed the brakes all of a sudden worked and the veh. came to a sudden stop.
I took the veh. back in to Hyundai next day and it's been there over a month and a half. They determined that they would have to replace the IEB unit but couldn't find the schematic to get a part# to order by. They eventually found the part # and the unit should be here by Sept. 12 although I'm not holding my breath.

 

Yes, I'll see what I can do.

 

It's an expensive unit and that's why I'd suggest that periodic brake fluid changes are more important than in ICE cars. The blended braking is also a vehicle feature that Tesla doesn't have.
https://www.hyundaipartsdeal.com/genuine/hyundai-unit-assy-integrated-electric~58520-k4000.html?vin=&make=Hyundai&model=Kona Electric&year=2020&submodel=&extra1=&extra2=&filter=(DT=R)

 

Interesting, the "main actuator" is a screw-driven piston rather than a pressure accumulator valved in, like
the Prius infamously had [and which made all kinds of mysterious noises]. I haven't found any good doc
on its workings, but again, well-blended regen braking is one of the more complex aspects of the car.

_H*

 

So today while driving, my brakes failed. Luckily I was already reducing speed when the brakes failed but still unable to stop in time and hit the vehicle in front of me which was stopped for a red traffic light. No major damages (minor scratches/indentation) but really lucky that there was a vehicle otherwise I would have gone into the intersection and either get T-boned or T-bone someone. I am now waiting for a tow truck to come and tow the car to the dealership to look at as I am not willing to drive the vehicle. Alert given was "Stop Vehicle and Check Regen Brakes" with all warning lights lit up.

 

Update: The dealer said that it wasn't just the "Stop Vehicle & Check regen brakes" light that came on, he said that it was every other lights. Now they managed to turn off all the lights (reset) and went through but could not find anything wrong other than that a part needed to be replaced and that it will take about a month for the part to arrive. In the meantime, they have driven the car and found no problem and if I wished, I can leave the car with them until the part arrive or drive the car home while they arrange to have a loaner vehicle for me since it is a safety issue. It will take a couple of days to arrange for the loaner so I drove my Kona home (without any issues) but was driving very, very cautiously like making sure that I stay below the speed limit and that I take my foot off the gas pedal and gently press down on the brake pedal after ensuring that regen braking was working. I did not understand which part requiring replacing but guess I will find out when it arrive.

 

I'll just interject here that I had a serious failure of my car with all warning lights blazing combined with a loss of drive power and it was the result of a bad accelerator pedal assembly.

 

You are right, I've had no time to engage the EPB with the regen brakes not working, first instinct was then to jam on the brake pedal and when that didn't work, pump the pedal and by that time, the car has hit the stopped vehicle in front. Like I said, I was lucky that I was already slowing down & coasting before the failure (foot off the gas pedal). Will need to keep the EPB in mind in the future.

 

The dealership approved the Service manager's request for a rental for me (safety issues given the failure of the brake system). He confirmed that they will be replacing the ABS module as soon as they the part delivered. I am now back to driving an ICE vehicle and have to buy gasoline again


As for the 12V battery, that's something to check out but my Kona is only 18 months old.

 

UPDATE: It's almost a month to the T and I got my Kona back. They replaced the ABS module and so far, day 1 drive seems to be okay although I am more cautious when driving leaving more a gap between the car in front and actually having a finger on the ePB when slowing down.

 

Before I forget, a fellow Kona owner on Reddit (Victoria, Canada) also has similar issues (warnings and loss of braking capability). Their dealership diagnosed a faulty ABS module and currently waiting for a replacement part.

Day 2 drive was fine with no problems or warnings.

 

Part no as listed on the invoice is 58520-K4000 which was described as "Brake Master Cylinder" with a MRSP price of CAD$4,625.00. This is the same part that KiwiMe mentioned above.


So far, I have driven the vehicle with no known issues. I do feel that it drives differently than before but that could be just me not being confidential in the vehicle.