Volkswagen ID.3 Forum

I followed a 22 plate ID.3 today and I have to say that the brake lights were constantly on and off . I can only assume that this is caused by the lifting of the throttle and the regenerative braking. This to me seems unsafe particularly if you are constantly adjusting the throttle in traffic.

Is this the case with all EV's as I haven't noticed it so much on any other EV make.

This can happen if you are in B mode and are on the threshold of completely lifting for a while - usually on a steady down slope. (I followed my wife in our ID3 and noticed it).
Not sure it’s dangerous, a little annoying sure.
Can’t say I’ve generally noticed it, so maybe VW need to make some adjustment.

Haven't followed an ID.3 so haven't noticed but can see it it could be annoying..... but not as dangerous as the lights not going on! I suppose VW have to err on the side of caution.

The same with many EVs, this phenomenon is particularly noticeable on the MINI Electric.

Car slows down due to braking, brake lights come on.. Not sure what you consider dangerous about that. As you have already said, if you are having to over react to the lights, you're driving too close.

G43FAN wrote: ↑Tue May 10, 2022 2:23 pm Car slows down due to braking, brake lights come on.. Not sure what you consider dangerous about that. As you have already said, if you are having to over react to the lights, you're driving too close.

Not driving too close at all, but with the brakes lights constantly flashing you react to that braking, if you don't you inevitably get closer to the vehicle in front which is dangerous. It also causes traffic issues as you then get braking through the line of traffic causing congestion through a chain reaction. https://www.rac.co.uk/drive/advice/driv ... uses-them/

G43FAN wrote: ↑Tue May 10, 2022 2:23 pm Car slows down due to braking, brake lights come on.. Not sure what you consider dangerous about that. As you have already said, if you are having to over react to the lights, you're driving too close.

But technically they are not braking they are decelerating, there is a difference. Its not about over-reacting its about braking becuase you need to brake i.e. stop of you are slowing down. No ICE car's brake lights come on when you decelerate.

FrankNicklin wrote: ↑Wed May 11, 2022 8:06 am

G43FAN wrote: ↑Tue May 10, 2022 2:23 pm Car slows down due to braking, brake lights come on.. Not sure what you consider dangerous about that. As you have already said, if you are having to over react to the lights, you're driving too close.

But technically they are not braking they are decelerating, there is a difference. Its not about over-reacting its about braking becuase you need to brake i.e. stop of you are slowing down. No ICE car's brake lights come on when you decelerate.

So you want brake lights on if someone presses the brake pedal, but not if the car is using other means to slow down, like hard engine braking or regen deceleration. Sorry, but that's nuts. Brake lights are there to warn you that the car in front is slowing down, so you can be aware and maintain a safe distance-you should want to know this no matter how the car is slowing, beyond a certain threshold.

Many ICE cars decelerate for you with the likes of ACC and hybrid/regen technology, and when they do, they'll activate the brake lights.

Agree that to only have the brake lights activate in response to pedals or to the pads engaging would be utterly bonkers. Like someone else said, if brake lights turning on/off feel dangerous then you need to be further back.
I think if there is an issue here it is that the ACC will sometimes modulate throttle and regen in traffic at higher frequency than a human using the pedals, and if it happens to be doing that around about the deceleration trigger point for the brake lights, then they will flicker on/off. I don't think it's a significant problem personally and it certainly can't be unique to the ID.3.

FrankNicklin wrote: ↑Wed May 11, 2022 8:06 am

G43FAN wrote: ↑Tue May 10, 2022 2:23 pm Car slows down due to braking, brake lights come on.. Not sure what you consider dangerous about that. As you have already said, if you are having to over react to the lights, you're driving too close.

But technically they are not braking they are decelerating, there is a difference. Its not about over-reacting its about braking becuase you need to brake i.e. stop of you are slowing down. No ICE car's brake lights come on when you decelerate.

The car is actively reducing the speed of the car, I think that's braking? If they were in D the car wouldn't slow as quickly and there would be no lights.

I certainly want people behind me to know that my speed is reducing. The rate at which it reduces determines if the brake lights come on or not. It's not about "deceleration".

The person behind me shouldn't care if it is caused by "B" mode, the brakes, my reverse hamster wheel*, or anything else. All they need to know is that I'm slowing down and to respond accordingly.

* only available as an option in Spain

Anduain wrote: ↑Wed May 11, 2022 1:06 pm my reverse hamster wheel*,

* only available as an option in Spain

Does this involve sticking your feet out through the floor (as per The Ant Hill Mob)?
Is it only available on Max or all trims?

Griff wrote: ↑Wed May 11, 2022 1:19 pm

Anduain wrote: ↑Wed May 11, 2022 1:06 pm my reverse hamster wheel*,

* only available as an option in Spain

Does this involve sticking your feet out through the floor (as per The Ant Hill Mob)?
Is it only available on Max or all trims?

It does and 21 Max only I'm afraid.

I guess it’s a little surprising that you get a prolonged brake flicker with regen braking. You’d think either a threshold was exceeded and fully applied for a while or not. To jitter around a threshold triggering lights on and off seems a bit odd.

Can someone clarify a point? Whatever mode the car is in, do the brake lights only come on if the car is actively slowing down? Put another way, does simply maintaining speed on a downslope count as "braking"? Does reducing pedal pressure on an upslope which slows the car even though the motor continues to deliver forward power, count as "braking"?

I assume regulatory bodies produce rules about this sort of thing. Decades ago these were simple little booklets, but I suspect these days they come in thousand-page pdfs.

Yes TimF, with real maths

viewtopic.php?f=8&t=298&p=1056#p1056

mediaguy wrote: ↑Fri May 13, 2022 8:41 am Yes TimF, with real maths

viewtopic.php?f=8&t=298&p=1056#p1056

Thanks. So the system must show brake lights for a deceleration above 4mph/s, must not for one below 2mph/s. (I find it difficult to think of road speeds in terms of m/s!) I think that means they'll come for almost anything other than coasting.

Somewhere I read the ID series have break lights controller by accelerometers so if the car slows down by more the a prescribed rate see previous reply the break lights come on and has no dependance on pressing the break pedal.