# New Code: Change of the Brake Force Display in NA.



## JEG23 (Jun 4, 2011)

Brake Force Display (also known as Adaptive Brake Light or Dynamic brake lights) shows the drivers behind that you are braking suddenly and with force.

In North America (NA), during normal brake application, the outer brake lamps light up.

During heavy brake application, the inner brake lamps also light up.









In Europe, the display of Brake Force is different. Instead of the extra lights, the brake lights flash rapidly during heavy brake application.

This is a matter of preference, but recent studies carried out by Daimler Benz show that people's reaction time is quicker with flashing brake lights than without. The studies found that at a speed of 50 mph the increased reaction time reduces the stopping distance by approximately 14.5 feet and at 65 mph by around 20 feet. That's nearly 2 car lengths.

If you are wondering about the legality of this change in NA, I am not an expert on this, so the truth is that I am not certain. I found the following quote during a search "the National Highway Traffic Safety Administration awarded the U.S. subsidiary of the German luxury car company [MB] a temporary exemption from U.S. automobile safety standards, allowing it to sell as many as 5,000 vehicles over the next two years that include brake lights that flash during emergency stops." If you search this topic, there are opinions galore. Please, do not flame me with your opinion on this. I am only showing you that this change is possible.

It requires the following code change to set how your brake force is displayed:

*FRM->3050 FRM_AUSSENLICHT_PARAMETER, 30->ESS_ERSCHEINUNGSBILD->bremslicht blinkend (brake light flashing). The default (at least in NA) is flaechenvergroesserung (area enlargement)*

You can adjust the sensitivity of the system with the following codes:

*FRM->3050 FRM_AUSSENLICHT_PARAMETER, 30->ESS_ON_VERZ (default for Europe (14 dec) 10 m/s2; default for US (10 dec) 8 m/s2)*
This refers to deceleration speed

*FRM->3050 FRM_AUSSENLICHT_PARAMETER, 30->ESS_GESCHW_SCHWELLE (default for Europe Werte=32 (50 dec) default for US Werte=05 (5 dec))*
This refers to the threshold speed for activation

Again, this is a matter of preference. Use at your own discretion. Also see attached a study by the National Highway Safety Administration of enhanced brake lights. They compare flashing brake lights to increased light output. It speaks for itself.

Many thanks to Miotoo and Sean for their help. None of these code changes are possible without the resources, tools and advice provided by Shawn, Sean and others.

JEG23


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## Chuck W. (Apr 27, 2007)

I like it. And will have it coded.


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## JEG23 (Jun 4, 2011)

Chuck W. said:


> I like it. And will have it coded.


:thumbup:

I also have on in mine and the way I drive, I am sure it is annoying the heck out of a bunch of drivers behind me. To be honest, I will do whatever is necessary to make those texting drivers look up and pay attention.

JEG23


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## shawnsheridan (Jan 10, 2009)

Awesome! This one warrants the coveted 6th Banana JEG, because unlike most of your other recent discoveries, which sadly required options my car doesn't have, this one I can actually use.

:freakdanc :freakdanc :freakdanc :freakdanc :freakdanc :freakdanc


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## Boardman (Jan 5, 2013)

The sixth banana. Hahaha


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## JEG23 (Jun 4, 2011)

shawnsheridan said:


> Awesome! This one warrants the coveted 6th Banana JEG, because unlike most of your other recent discoveries, which sadly required options my car doesn't have, this one I can actually use.
> 
> :freakdanc :freakdanc :freakdanc :freakdanc :freakdanc :freakdanc


Shawn,

I am touched. I thought 5 bananas was the highest accolade.

Time to make banana bread again.

JEG23


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## shawnsheridan (Jan 10, 2009)

JEG23 said:


> Shawn,
> 
> I am touched. I thought 5 bananas was the highest accolade.
> 
> ...


Oh no...there is room for improvement...kill VMAX, solve Internt-In-Motion, and Sport Mode by default, and it will rain down Bananas my friend.


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## JEG23 (Jun 4, 2011)

shawnsheridan said:


> Oh no...there is room for improvement...kill VMAX, solve Internt-In-Motion, and Sport Mode by default, and you will rain down Bananas my friend.


You are a hard task master


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## shawnsheridan (Jan 10, 2009)

JEG23 said:


> You are a hard task master


I know...but I can't let you rest on your laurels...you are capable of so much more...


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## markgca (Jan 21, 2013)

JEG23 said:


> *FRM->3050 FRM_AUSSENLICHT_PARAMETER, 30->ESS_ON_VERZ (default for Europe (14 hex) 10 m/s2; default for US (10 hex) 8 m/s2)*
> This refers to deceleration speed


if the study is correct, and it seems reasonable, we will need to experiment further with at least the first parameter.

the european default of 10 m/s2 converts to about 1 g (there are many on line convertors, http://easycalculation.com/unit-conversion/acceleration-converter.php ) 
the us default of 8m/s2 converts to about .8 g

But, the paper cited determined that the optimum trigger was about .35 g, which converts to about 3.43 m/s2

IF that conversion is correct, we need to figure out what parameter for ESS_ON_VERZ corresponds to the 3.43 m/s2 number to give us the best result.

any idea how to do that? or is the result simply linear that we can interpolate from the two data points cited?


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## JEG23 (Jun 4, 2011)

markgca said:


> if the study is correct, and it seems reasonable, we will need to experiment further with at least the first parameter.
> 
> the european default of 10 m/s2 converts to about 1 g (there are many on line convertors, http://easycalculation.com/unit-conversion/acceleration-converter.php )
> the us default of 8m/s2 converts to about .8 g
> ...


markgca,

Great! This is the type of conversation I was hoping this posting will elicit.

I agree with you. The current setting, even in the US, requires what I would describe as a "violent" stop to trigger the flashing.

If you want 0.35 g you will have to set ESS_ON_VERZ to a werte of 7. That will result in the brake lights flashing at a more reasonable sudden stop. As you say, the NHTSA study used 0.35 g as their test deceleration.

By the way, both the MB and the NHTSA studies used 5hz flashing rates for the brake lights, which is the default setting in our cars. I personally do not understand why it takes so much time for NHTSA to mandate something that is obviously beneficial.

Thanks for your input.

JEG23


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## shawnsheridan (Jan 10, 2009)

JEG23 said:


> ...
> 
> *FRM->3050 FRM_AUSSENLICHT_PARAMETER, 30->ESS_ON_VERZ (default for Europe (14 hex) 10 m/s2; default for US (10 hex) 8 m/s2)*
> This refers to deceleration speed
> ...





JEG23 said:


> ...
> 
> If you want 0.35 g you will have to set ESS_ON_VERZ to a werte of 7. That will result in the brake lights flashing at a more reasonable sudden stop. As you say, the NHTSA study used 0.35 g as their test deceleration.
> 
> JEG23


FYI. I think you made a mistake in your initial post, as the vlaues you give for Werte in HEX are actualy the values converted into Decimal, so the resulting m/s ^ 2 are off:

US = Werte 0A (HEX) = 10 (DEC) = 10 x 0.5 m/s ^ 2 = 5 m/s ^ 2 = 0.509858106 g's
ECE = Werte 0E (HEX) = 14 (DEC) = 14 x 0.5 m/s ^ 2 = 7 m/s ^ 2 = 0.713801349 g's
ECE_M_Sport = Werte 10 (HEX) = 16 (DEC) = 16 x 0.5 m/s ^ 2 = 8 m/s ^ 2 = 0.81577297 g's

Your Werte 7 is good though:

Custom = Werte 07 (HEX) = 07 (DEC) = 7 x 0.5 m/s ^ 2 = 3.5 m/s ^ 2 = 0.356900675 g's
:thumbup:


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## JEG23 (Jun 4, 2011)

shawnsheridan said:


> FYI. I think you made a mistake in your initial post, as the vlaues you give for Werte in HEX are actualy the values converted into Decimal, so the resulting m/s ^ 2 are off:
> 
> US = Werte 0A (HEX) = 10 (DEC) = 10 x 0.5 m/s ^ 2 = 5 m/s ^ 2 = 0.509858106 g's
> ECE = Werte 0E (HEX) = 14 (DEC) = 14 x 0.5 m/s ^ 2 = 7 m/s ^ 2 = 0.713801349 g's
> ...


Shawn,

I stand corrected. I forgot to include the correction factor The US setting is not that far (0.5g) from the one used by NHTSA (0.35g).

Thanks.

JEG23


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## JEG23 (Jun 4, 2011)

JEG23 said:


> Shawn,
> 
> I stand corrected. I forgot to include the correction factor The US setting is not that far (0.5g) from the one used by NHTSA (0.35g).
> 
> ...


I am voluntarily giving you one of my bananas back :banana:

JEG23


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## shawnsheridan (Jan 10, 2009)

JEG23 said:


> I am voluntarily giving you one of my bananas back :banana:
> 
> JEG23


Thanks...but that is not the Banana I gave you...that's somone elses Banana...


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## JEG23 (Jun 4, 2011)

shawnsheridan said:


> Thanks...but that is not the Banana I gave you...that's somone elses Banana...


Shawn,

I only accept bananas from you. It might be a bit black, but it is your banana 

JEG23


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## shawnsheridan (Jan 10, 2009)

JEG23 said:


> Shawn,
> 
> I only accept bananas from you. It might be a bit black, but it is your banana
> 
> JEG23


Hmmm...mine all look like :freakdanc.

This :banana: though, is an inferior Banana.


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## JEG23 (Jun 4, 2011)

shawnsheridan said:


> Hmmm...mine all look like :freakdanc.
> 
> This :banana: though, is an inferior Banana.


I stand corrected (again) :freakdanc

:bawling: JEG23


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## markgca (Jan 21, 2013)

JEG23 said:


> markgca,
> 
> Great! This is the type of conversation I was hoping this posting will elicit.
> 
> ...


my suspicion is that they were studying what was already being used in europe, which is why its what bmw is now using. 
for some reason we are way behind europe on a lot of issues due to some of our stupid laws/lawmakers.

its true for our speed limits (first set by highway design of 75mph, then by oil embargo to 55, now by safety to 65) none of which has any true science behind them for todays cars.

its true for our crash testing limits; we used to try to explain to them that if you allowed for a little bit larger leg impact (ie more broken legs) at slower speeds we could protect occupants to higher speeds, but they ignored pretty much any input.

the same thing was true for our lighting systems; europe had vastly superior halogen lighting for years before the US adopted it. fortunately you could convert your car over, and i did so for over 20 years. How many people died/were in accidents because their lighting was so poor?

now its this. and im not going to get into the cafe mileage requirement, set by the same idiots who think raising our taxes will solve any overspending issues they have.

i used to work for Highway Safety Research back in the 70s. The bad news is that these reports make a ton of assumptions to get to their answers, and we dont really know whats real and whats made up, and certainly dont know what other variables should be studied.

nevertheless it certainly seems that blinking is better than nothing. but we dont have 'nothing', as we have the 2 stage lighting.

the US BMW's DO increase lighting intensity (sorta) by lighting up the 2nd/inner panel under harsh braking. what i dont know is how bright each segment is - as it might already be 'bright enough' per that paper and not get any additional warning. on the other hand, they didnt study the effect of an additional panel of lights coming on (the 2nd stage lighting effect), so it may be almost as effective as the blinking? who knows....

maybe bmw DID study these effects, and thats why they put the 2 stage lighting/extra brake lighting panel on our cars?


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## shawnsheridan (Jan 10, 2009)

markgca said:


> ...set by the same idiots who think raising our taxes will solve any overspending issues they have.


:thumbup:
Are you sure you are from California though as you are at odds with damn near all the rest of your state?


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