Automatic stopping and rear brake lights? | Kia EV Forum
Kia EV Forum banner

Automatic stopping and rear brake lights?

4.8K views 16 replies 5 participants last post by  rkr  
#1 ·
When using brake hold (car at stop and holds without foot on brake,) do the rear brake lights show ON?
When using Auto Regeneration with full stopping (without using brake,) do the rear brake lights show ON?
Thanks.
 
#2 ·
Auto hold when completely stopped, yes.

auto regen when in level 2 (what I use on my GT Line) when you completely let go of the brake pedal, the light comes on. I use regen paddle on the left to come to a complete stop and it still has the brake light on. once at a complete stop I hit the brake pedal to engage the auto hold which leaves the brake light on. This was confirmed by my wife who followed me and I also who followed her.
 
#6 · (Edited)
Auto regen with full stopping: That's what i-pedal (what everyone else calls 1-pedal) does.

Be warned that the brake lights are only illuminated when you completely (or nearly completely) lift-off the accelerator -- without regard to the rate of speed descent. For regen mode Lvl 1 and Lvl 2, the relatively light regen results in a slow descent in speed so not a big deal.

For Lvl 3, the regen is more forceful. But for i-pedal, it's possible for the car to quickly slow to a complete stop without displaying the brake lights until you are (nearly) motionless. This can happen if you try to modulate your stop without completely lifting off the accelerator. That is a really big deal.

I installed a brake light monitor on my dash that's tied into the 3rd brake light circuit so I can see when (and when not) the brake lights are illuminated when using i-pedal (I love i-pedal and use it exclusively for in-town driving). I've had people rapidly closing on my tail when I was slowing for a stop or a turn using i-pedal. Curious as to why that was happening, I installed my brake light monitor and quickly had my answer.

Alec, of Technology Connections (a pretty good Youtuber) just released a video describing this in far greater detail. He drives an Ioniq 5 but this applies to the EV6 as well. If you use Lvl 3 or especially i-pedal, this video is required viewing. Alec characterizes this "defect" as recall worthy. I agree.

 
#16 ·
I installed a brake light monitor on my dash that's tied into the 3rd brake light circuit so I can see when (and when not) the brake lights are illuminated when using i-pedal (I love i-pedal and use it exclusively for in-town driving). I've had people rapidly closing on my tail when I was slowing for a stop or a turn using i-pedal. Curious as to why that was happening, I installed my brake light monitor and quickly had my answer.
Is there someplace where I can get the "how to" on tapping into the brake light power wire?
 
#7 ·
We live in SE FL, where some (maybe most) of the world's worst drivers live. Almost a week doesn't go by without someone being rear-ended. And, as far as I am concerned, this thread is a life-saver and should be elevated for all to see. Here's what I gained about braking safely from this excellent video - and from the replies. Please correct any incorrect statements:

1. It is OK for me to use smart cruise control as the brake lights do go ON when slowing down
2. It is OK for me to use regen levels 1 and 2 as the video shows that the brake lights do go ON as the car slows down
3. It is OK for me to use Auto Hold as the brake lights are ON when car is in Hold
4. It is NOT OK for me (you can use, but know that your will be at risk for an accident) to use any of the other regenerative options as the brake lights will go ON only when at a full stop (or foot on brake pedal) and not as the car slows down during regeneration caused braking
 
#8 ·
4. It is NOT OK for me (you can use, but know that your will be at risk for an accident) to use any of the other regenerative options as the brake lights will go ON only when at a full stop (or foot on brake pedal) and not as the car slows down during regeneration caused braking
Let me correct/clarify your comment slightly. Even in i-pedal mode, if you completely lift-off the accelerator, the brake lights will come on. So that's good. BUT, hardly anyone does that in i-pedal mode. As Alec mentions in the video, when using i-pedal, one normally modulates the accelerator inside the regeneration band -- that portion between foot-off and foot-on hard enough to maintain speed. In the video, Alec explains that as -25% to 0%.

And that's the problem. The brake lights don't come on during regen braking if you are modulating the accelerator for a more gentle slowdown -- only if you completely lift-off. Which, in i-pedal, results in an uncomfortably abrupt slow-down to an eventual smooth stop.

As Alec explains, this isn't against code because the code is obsolete and never considered all the ways a car can be slowed these days -- beyond just coasting.
 
#13 ·
I found this directly from Kia:

"The rear brake lamps may activate while the vehicle is using regenerative braking. The brake lights will activate depending on how quickly the vehicle is decelerating.

  • Deceleration not greater than 0.7 m/s² (meters per second squared) = Brake lamps will not activate
  • Deceleration between 0.7 m/s² and 1.3 m/s² (meters per second squared) = Brake lamps may activate
  • Deceleration greater than 1.3 m/s² (meters per second squared) = Brake lamps will activate"
However, I really don't understand the speed relationship to the various regen braking options. Could someone offer an explanation showing how the speeds relate to Level 1, 2...Auto...i-pedal braking and the rear brake lights going ON? Thanks.