Some electric vehicles, including several GM EVs, are equipped with a one-pedal driving system that will slow the vehicle down without the driver touching the brake pedal. Basically, the driver simply needs to remove their foot from the throttle, and the electric vehicle will slow down. The question then becomes this – how do drivers behind the EV know that it is slowing down if the brakes aren’t used?
While it may seem like a simple issue, the proliferation of new electric vehicles throughout the automotive industry makes this a valid question for many drivers, including not only first-time EV users, but other drivers on the road as well.
Luckily, the answer to this question is pretty straightforward – when it comes to GM electric vehicles, the rear brake lamps illuminate as soon as the vehicle starts to decelerate. This includes vehicles equipped with one-pedal driving, as well as the Regen on Demand paddle on specific GM models.
Notably, the Chevy Bolt EV and Chevy Bolt EUV both include a section in the owner’s manual that states the following:
“The brake lamps may come on when the accelerator pedal is released or during substantial deceleration from regenerative braking.”
Additionally, the GMC Hummer EV and Cadillac Lyriq both include a section in their respective owner’s manuals that states the following:
“The brake lamps will come on during substantial deceleration and when the vehicle is stopped.”
So, to answer the question directly – drivers behind an electric vehicle that is decelerating due to one-pedal driving will know that it is slowing down thanks to the EV’s illuminated brake lamps.
GM has announced plans to offer 30 new electric vehicles globally by mid-decade, with 40 percent of the automaker’s U.S. model lineup being all-electric by the end of 2025. General Motors has also announced plans to eliminate tailpipe emissions from its new light-duty vehicles by the 2035 calendar year, and to achieve full carbon neutrality by 2040.
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Comments
Does the Cadillac Escalade brake lights come on when in Super Cruise and the vehicle in front slows down causing the Escalade to a lesser speed?
How about non-GM cars? Does a regulation on brake light activation under regen exist? Or will we all need forward-looking radar or LiDAR to detect deceleration in the car in front?
Having been badly (totaled) rear-ended on the highway traveling at 70mph without braking at all and the one that hit us in the rear must have been going 95mph, I hope all cars are required to have radar/LiDAR auto-braking in the future!!!
Most likely all vehicles will have forward looking braking. If not the lawyers will line up stating that it’s not a safe vehicle without it. This technology needs to go in 18 wheelers and all HD trucks.
Just so long as it’s done right. Honda Civic drivers have complained that the 2016-2021 series had phantom braking that brought them to a complete stop on the highway with nobody in front of them. It spooked them so much that they never trusted it since.
We don’t need more regulations, we need better drivers.
We need regulations requiring better driver training and testing.
Dennis, all Teslas have the brake lights come on under regen – the display always shows you when the brake lights are on. In the case of Tesla it is quite sensitive and comes on even when deceleration is mild. This not the case for the Bolt which requires greater deceleration to engage the brake lights. My prior Volt never engaged the brake lights under regen conditions.
“may come on” –I may have won the lottery last night.
I run my Bolt 500 miles for 20bucks in electricity. Try doing that with your turbo diesel. PS, you’ll never coal roll me either, I’ll always be ahead of you.
EV trucks only go 90 miles while towing.
Your Bolt won’t haul my tools or pull my trailer.
Sounds like you might have to step up to a Maverick in your situation. Not every style vehicle is right for everyone. I’m hanging on to my 2015 🌮 for now. If Cybertruck specs and pricing works out, I’ll do that. No current truck offerings suit my fancy, but I do need one.
Your gas powered truck produces at least 4 1/2 tons of CO2 per year which is killing our atmosphere and adding to the problem of global warming.
Its killing absolutely nothing. In fact earth is greener thanks to elevated levels of CO2.
the abysmal level of ignorance that you show is astounding. You are correct that an electric truck is not the best choice to tow a large load across the country BUT for 90% of everyday driving an electric car is a perfect, low cost fit. Since most people have two vehicles, making one an electric is an acceptable answer. As for you flippant answer about CO@ levels and a greener earth… well everyone is entitled in this country to be ignorant and to ignore realities.
Rich, according to NASA, the earth is at least 14% greener overall due to rising CO2 levels over the past 35 years. This is despite continuous urban sprawl. Another fact is that Earth’s CO2 levels have gone up from .03% of the atmosphere to 0.04% currently. This information is readily available through NOAA and NASA. Regardless of what everyone on here thinks about global warming, the fact is that many other carcinogens and pollutants are also released from tailpipe emissions and recent studies in California have shown that asthma and air pollution have dramatically decreased with the recent rise of BEVs. It will be interesting to see the long term health benefits of reduced ICE emissions. The BEV revolution is coming whether these truck drivers who apparently pull trailers 100% of the time think. Even if 100% of the electricity came from coal plants (which currently produce less electricity than renewables in the US) CO2 emissions and pollutants would still be reduced by at least 50%. And yes, BEVs are the best answer given the significant hurdles facing H2.
Thank you for this article about regen braking and deceleration lighting. I often wondered about this and how I could test to discover the answer.
This article reminded me when many cars and trucks had manual transmissions. Some would use engine braking and slowly come to a stop barely needing to touch the brake. Then the driver would sit at a traffic light without the brake pedal depressed, therefore no brake lights. From a distance you could not always be sure if the vehicle was stopped or just moving.
Saying brake lights come on during ‘substantial’ deceleration continues to make me wonder – when is deceleration substantial enough for my brake lights to come on?
Among the dashboard gauges, there should be a light that turns on when the brake lights light up. No more wondering.
StuartH: I kind of thought the same thing when I got my Bolt. But I was able to answer my own question there by watching in my rear view mirror and could tell (in darker lighting of course) when the brake lights came on. I was truly concerned about that and I didn’t feel the book gave a very reassuring answer. What I found out is as soon as I lift off the gas pedal, the brakes lights come on when in one pedal drive. I’ve “tested” it when lifting off the gas fully (lights come on) and then just barely applying pressure back to the go pedal and the brake lights go back off. I use one pedal drive all the time and love it.
That is the first thing I noticed too Larry. Why would they use misleading pictures showing the tail lights lit while talking about the brake lights. They moved the brake lights to the lower position which is my one big gripe about the 2022 refresh. I will remember this article if I ever get rear ended in my 2023 EUV. Come on Chevy you know this was a bad decision. FIX THE LIGHTS. Thank you.
My 1986 Cutlass Supreme Brougham had 3 small lights at the top, inside in the back of the car, that you could see when you looked out your rearview mirror. One of them was illuminated when you hit the brake, and I think one was for turn signals on and I don’t remember what the 3rd one was for.
tbiede: My parents owned numerous vehicles with those. I’ve also sold many with them (Buick and Cadillac). Currently, I own a 2023 Bolt EV, 1988 Cadillac Cimarron and 1986 Cadillac Seville. Of the 3, only the Seville has the red “cat eyes” above the rear window on the inside. The are dim red when lights are on, brighter red with brakes and blink with turn signals on. It also has the front fiber optic lamps for the high, low and turn lights. I love those things and wish new cars had them.
“Lol what an idiot”
What GMC Fan says when they look in the mirror.
Every Tesla does this – the car display always shows you what lights are on, including brake lights. This should be a feature on the Bolt display. I’ve noticed when following Bolts in traffic that I don’t see their brake lights unless it is rapid deceleration (foot off or close to it) or being stopped. As people learn one pedal driving, they become better at delivering a smooth ride which minimizes hard acceleration/deceleration and brake lights. From my experience the Tesla threshold is much slower decel than the Bolt for engaging the brake lights.
FJB
And Mary.
Do you notice that all the photos of the Bolt have the taillights lit, not the brake lights. Do you admit you made a mistake Chevy
EV batteries are also worse for the environment than oil drilling. Fracking actually cleans the water that comes out of it.
This would be laughable except that I think you mean it.
Evidence, please.
That is the first thing I noticed too Larry. Why would they use misleading pictures showing the tail lights lit while talking about the brake lights. They moved the brake lights to the lower position which is my one big gripe about the 2022 refresh. I will remember this article if I ever get rear ended in my 2023 EUV. Come on Chevy you know this was a bad decision. FIX THE LIGHTS. Thank you.
Just to help clarify. If the GM cars are like Tesla’s, the brake lights don’t come on every time you let off the accelerator. The car turns them on when you decelerate at a speed that would be similar to someone pushing the brakes. If I ease up to drop my speed for whatever reason they won’t come on. That would be the equivalent of an ice car brake lights coming on when they are coasting to a stop. It’s unnecessary and confusing to other drivers. Tesla’s show the car on the screen and the brake lights come on the display car to show you what your car is doing, so you know exactly when the lights are activated.
The author misstates what GM indicates in the manual. The author says, “The brakes lights come on as soon as the car starts to decelerate.” However the manual indicates ” substantial deceleration “
The driver following my car will see that as soon as I stop, the brake lights go out because I can keep my car stopped without stepping on the brakes. They are responsible to keep their distance and avoid hitting me. After fifty years of stopping this way, no one has dared to hit or touch my cars.
The whole 1 pedal driving doesn’t even make much sense. You can’t coast along, you always have some sort of energy being fed to the wheels or being scavenged from braking. How about regenerative braking when you actually push the brake pedal instead of just when you lift off the accelerator? A hundred years of automobiles has had them separate for control reasons.
One pedal driving doesn’t bother me at all. Works just like my tractor. It’s my truck I struggle with. It requires using the extra pedal.
You can set the car up how you want it and yes regen does work when you press the brake and decreases as you push it harder using friction to stop. Once one pedal driving is mastered, it is a superior driving experience and quite efficient. Once you get used to it, its hard to go back – even driving a Porsche Taycan sucks as it doesn’t have one pedal driving – not all BEVs do. The Bolt and Teslas allow you to set the degree of regen.
mvb: Well said. Now that I’m so used to driving with the one pedal system, I do find it difficult to adjust back to the outdated systems that don’t use it.
I find it quite funny how many people will just toss a comment up when they don’t know or understand what it is they are commenting on. This is why I truly feel the industry must do a better job at educating buyers on EV’s and PHEV’s. Until a person is better educated, they can’t make a rational buying decision.
Dan B, most of the commenters on this site are staunch anti-BEV with preconceived partial truth talking points, yet most of them have never even been in an EV. Once you own one, there is no going back. I get in my 2020 ZR2 diesel and it feels archaic and can’t wait to trade it in on a truck BEV. Like 95% of truck owners I don’t haul a heavy @ss trailer every day, but when I do, I know my fuel economy will be 1/2 just like a BEV truck. The current benchmark of the 9k pound HUMMER EV or the half @ssed F-150 Lightning is pretty low and clearly makes a strong argument for ICE in this arena for now. That will change as these BEVs get lighter and more efficient with charging stations as ubiquitous as gas stations. While on the horizon, some former Tesla engineers started a company building camper trailers with batteries and solar panels that will allow for long distance remote overlanding that will surpass current ICE capabilities. BEVs are superior in slow travel with frequent regen opportunities – my truck can go about 500 miles on the highway with a full tank (and driving close to the speed limit), but less than 1/2 of that in FWD off road, but BEVs are more efficient in this setting.
I absolutely agree. A lot of anti EV people on the site only know what they hear on certain media outlets that are beholding to their big oil customers.
I will never buy another ICE vehicle. I love one pedal driving and when I drive my Honda HRV it feels like something is wrong with it.
My Chevy Bolt is the best car I’ve ever owned and I’ve had many. Chevy really needs to step up production of the Bolt.
Re: Chevy Bolt. The brake light comes on after brake regeneration hits negative 18 when you use “L” or one pedal driving. If you do not like the brake lights to turn on when you lift off the pedal, just use “D”. Regeneration will never reach negative 18 to activate the brake lights while using “D” which is non one pedal driving.
Seems like a change is needed. Like motorcycles, as the brakes are applied, the brake lights will flash before going steady. Makes sense for EV as when there is just a slight deceleration, the brake lights should flash until braking is applied.
When it comes to GM electric vehicles, the rear brake lamps illuminate as soon as the vehicle starts to decelerate. This includes vehicles equipped with one-pedal driving,
This is a badly written article. one part says may and what I wrote above.
When I tested the 2020 model of the Bolt I had a friend with me. I also wondered if the brake lights came on when I took my foot of the accelorator. Did the test in a large empty lot and my friend said the lights came on right away.
I do mostly one-pedal driving with my 5MT Sonic. Start deceleration early for curves and for red lights, especially with traffic waiting. Not many downshifts required and brakes last beyond 100k.