Hyundai to update EV brake lights; our tests show how they currently may not come on

Hyundai will be launching a “field service campaign to update the EV brake light logic” on its Ioniq 5 as well as the Genesis GV60, Electrified GV70 and Electrified GV80. According to Hyundai’s director of communications, Michael Stewart, the change will be make to new production vehicles and as part of free-of-charge service campaign that will launch in July for approximately 56,000 vehicles already on the road. 

“Regardless of the accelerator pedal input, the brake lights will now turn on when the deceleration rate exceeds approximately 0.13 G,” Stewart wrote in an e-mail to Autoblog. This change would seem to be in keeping with the behavior we have experienced in the Hyundai Ioniq 6, the firm’s most recently introduced EV. We go into that behavior lower in this article. 

This announcement comes in the wake of owner complaints as well as a test by Consumer Reports that found that most Hyundai, Genesis and Kia electric vehicles can come to a stop without their brake lights illuminating (Kia is also part of the Hyundai Group, but did not have a comment or update about a potential service campaign when contacted). This occurred when using those vehicles’ most aggressive “i-Pedal” function that allows for so-called “one-pedal driving” where the driver can mostly rely upon the car’s regenerative braking system (which is used to replenish the battery pack) to stop the car. 

We tested this for ourselves this week as we are currently testing a Genesis Electrified GV70, and I personally own a 2023 Kia Niro EV Wave. I almost exclusively drive in i-Pedal mode. News Editor Joel Stocksdale tested the Hyundai Ioniq 6 in Michigan, and again, we will address his findings after the Genesis and Kia as they are completely different.

I attached an action camera to the rear of each car and conducted the same test in both: Accelerate to 40 mph and come to a stop without touching the brake and, crucially, without lifting my foot fully off the throttle. The result as you can see below with the Niro is that the brake lights do not come on until around 3 mph when I fully lifted off the throttle and bring the car to a full stop. I could not bring the car to a full stop without fully lifting off the throttle. I experienced the same result in the Electrified GV70. 

The main conclusion: The brake lights need to be activated in this scenario, period, and it does seem like it would pose a safety risk. Cars behind you need to know you’re slowing down at a rate greater than is typical when lifting off a normal car’s throttle or even when engine braking with a lower gear. 

The secondary conclusion: This is a very specific scenario and not necessarily a common one. The video demonstration above is comparable to seeing a red light or stop sign far ahead, and making a clear decision to slowly feather the throttle in order to slow yourself down at just the right pace to “hit your mark,” so to speak, and come to a perfectly timed stop at the light or stop sign. If you lift off the throttle at any point, the brake lights come on. In other words, you have to try to do this. 

I do not agree with the Consumer Reports conclusion that the brake lights “do not illuminate as the car rapidly decelerates during one-pedal driving.” There was nothing rapid about this deceleration. The amount of slowing experienced is just slightly more than downshifting in a manual transmission car and using engine braking to slow — another scenario that would not engage the brake lights. What I would deem “rapid deceleration” requires fully lifting off the throttle and therefore engaging the taillights. 

Nevertheless, you can bring these tested cars almost to a stop without the brake lights coming on, and in fact, I probably do it quite a bit. As an owner of a Niro EV and user of i-Pedal, I would very much like and expect Kia to issue the same update Hyundai has now confirmed. 

Now, assuming that the “fix” described by Stewart above is the same as what’s already in place in the Ioniq 6, you can see the difference between the two thanks to the video below shot by News Editor Joel Stocksdale in Michigan. I will now turn things over to him. 

The video clip above is one of a few attempts of mine to see when and how the Ioniq 6’s brake lights activated. I put a GoPro on the back facing the center high-mount brake light in the spoiler, and set up my phone pointed at the instrument display. This way, I could see both when the lights came on, and the circumstances in which they did. I had the Ioniq 6 in Sport Mode in order to have the distinct blocks on the energy use and recovery gauge to more easily tell how much regenerative braking triggered the rear lights. And of course, I had the car in the most aggressive regenerative braking in order to come to a full stop.

This particular attempt, I brought the car up to about 30 mph, and then tried to lift off as little as I possibly could to initiate slowdown. My pedal work is a tad inconsistent as the parking lot where I was testing was fairly undulating. But the results are still clear, and clearly quite different from James’ experience in the Genesis and Kia. With only a little bit of lift on the throttle pedal, and my foot still very much on it, the brake lights came right on. In fact, it seemed that just two or three “blocks” on the regen gauge seemed to equate to what it took to trigger them. And in later driving, I was finding myself using much more regen than that regularly, both to adjust speed to traffic and for approaching a stop, since using such small amounts of regen would take a long time to fully stop.

Another important difference was the fact that, when coming to a full stop, the brake light would illuminate, and it would stay on even upon stopping completely. So if, for some reason, you’re not applying the brake pedal after coming to a stop at a stop light or sign, the brake light stays on to alert people that you’re stationary. It didn’t switch off until I reapplied the throttle.

This is clearly how these EVs’ brake lights should work when using i-Pedal and it’s good to know Hyundai already has a fix coming soon to existing owners. We now await word from Kia on whether it will get this service campaign.