# Disabling speed "KORREKTUR" -- success anyone?



## mhercz (Feb 21, 2006)

Greetings fellow coders.

I haven't been able to get the analog or digital speedometer to display uncorrected (accurate) values on my 2013 F10 M5. Still showing +3 mph at speeds over 60 mph as compared with my handheld GPS.

Per the cheat sheet v3, I changed "KOMBI 3000 Anzeige_Konfiguration BC_V_KORREKTUR" to nicht_aktiv aktiv / Werte=01 but that hasn't done the trick.

Any thoughts?


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## ilhan1103 (Dec 9, 2012)

You say it's +3mph now compared to your gps. How much was the difference before changing the value?


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## shawnsheridan (Jan 10, 2009)

I don't know that comparison to GPS is relevant. It is supposed to correct the Analog speedometer reading. How does the dial speedometer compare now to the digital speedometer in the BC Cluster assuming you enabled it with BC_DIGITAL_V = aktiv. I would expect a slight difference in the two after coding BC_V_KORREKTUR.


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## cn555ic (Mar 1, 2012)

On the E series there was a correction of 5mph...I would think this would hold true for the F series also


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## mhercz (Feb 21, 2006)

Many thanks for the replies. The values stayed the same after coding. 

FYI-- My display has the large digital speedometer underneath the analog gauge next to the time. Coding the BC to add the digital speedometer displays a second, smaller digital speedometer to the mutli-display at the bottom of the speedometer circle (where the mpg, range, date, etc. are displayed). 

All three are in sync and remain in sync with the Korrektur coded to activ or nicht activ.

Anything else to try?


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## shawnsheridan (Jan 10, 2009)

mhercz said:


> Many thanks for the replies. The values stayed the same after coding.
> 
> FYI-- My display has the large digital speedometer underneath the analog gauge next to the time. Coding the BC to add the digital speedometer displays a second, smaller digital speedometer to the mutli-display at the bottom of the speedometer circle (where the mpg, range, date, etc. are displayed).
> 
> ...


Ah yes, you have an M5, so you have the large Digital MPH readout already.

What if though BC_V_KORREKTUR is correcting all three readouts? Is it the same +3 over your GPS speed before and after coding?


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## mhercz (Feb 21, 2006)

Yup, the analog and both digital speedos read the same when the Korrektur is coded to activ vs. nicht activ: +3 at 60 mph measured against GPS. So it would seem the Korrektur isn't doing anything.


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## shawnsheridan (Jan 10, 2009)

mhercz said:


> Yup, the analog and both digital speedos read the same when the Korrektur is coded to activ vs. nicht activ: +3 at 60 mph measured against GPS. So it would seem the Korrektur isn't doing anything.


Strange. I don't know. :dunno:


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## mhercz (Feb 21, 2006)

Just found a CAF in HC2 that seems related: 3000 HC2_Codierdaten, 04 under Funktionen Korrekturkennline. The options are for various F models, and there's one option for Anlieferzustand. Any idea what this is?


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## shawnsheridan (Jan 10, 2009)

mhercz said:


> Just found a CAF in HC2 that seems related: 3000 HC2_Codierdaten, 04 under Funktionen Korrekturkennline. The options are for various F models, and there's one option for Anlieferzustand. Any idea what this is?


I don't know. My F10 doesn't have an HC2 module.

Looking at cafd_00000160.caf.003_004_010 though, the comment and translation is:
_
Kommentar=Parameter legt fest, welche Korrekturkennlinie verwendet wird.
Comment = parameter specifies which correction curve is used._

The question remains, a correction of what?


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## mhercz (Feb 21, 2006)

Mysterious. I'll try coding it various ways and see what happens. 

Leads me to wonder if there's an official BMW coding manual floating around somewhere . . .


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## shawnsheridan (Jan 10, 2009)

mhercz said:


> Mysterious. I'll try coding it various ways and see what happens.
> 
> Leads me to wonder if there's an official BMW coding manual floating around somewhere . . .


There is I am guessing. It is probably heavily guarded, on a red velvet pillow under a glass dome in Munich though.


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## mhercz (Feb 21, 2006)

Requiring a pouch filled with sand of equal weight to fool the booby traps . . .


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## shawnsheridan (Jan 10, 2009)

...someone cue up the theme to Mission Impossible and buy mhercz a plane ticket to Munich...


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## larrylotus (Nov 9, 2005)

Hi, same here. I also am trying to reduce the notorious german car speedometer overestimation error. On my 2013 F25 X3, it's about +3-4%. I am sure that it must be a simple and hidden coding parameter : X3 are used by law enforcement agencies and I bet that their speedos are dead on !

My issue is a little worse since I installed (voluntarely) slightly smaller circumference winter tires :-(

I have tried both settings on bc_v_korrektur with no noticeable difference, analog or digital...


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## dromader (Nov 21, 2009)

mhercz said:


> Greetings fellow coders.
> 
> I haven't been able to get the analog or digital speedometer to display uncorrected (accurate) values on my 2013 F10 M5. Still showing +3 mph at speeds over 60 mph as compared with my handheld GPS.
> 
> ...


Just to let you know that in new F30 for NA the bc-v-korrektur is aktif by default and it shows +3mph


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## shawnsheridan (Jan 10, 2009)

dromader said:


> Just to let you know that in new F30 for NA the bc-v-korrektur is aktif by default and it shows +3mph


Yes. aktiv is the default, and it means that BMW is correcting the speed. In this case, you want to disable it, so nicht aktiv is what is needed for true uncorrected speed.


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## dromader (Nov 21, 2009)

Aha I get it corrected means adding 3mph ... I'll try deactivate and see what happens


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## mhercz (Feb 21, 2006)

> Aha I get it corrected means adding 3mph ... I'll try deactivate and see what happens


Did coding the Korrektur to "nicht activ" make the +3 mph go away for you?


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## dromader (Nov 21, 2009)

Haven't have time yet, I plan to try it tomorrow or Friday ... I'll let you know if it works.


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## dromader (Nov 21, 2009)

I tried it but I see no difference 

I'll let the car sleep overnight and plug in my Garmin and compare


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## mhercz (Feb 21, 2006)

Any luck?
Got to think the Korrektur code does something, so maybe we're missing another code.


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## dromader (Nov 21, 2009)

In another thread recently somebody enabled the digital speedometer in addition to disabling the speed correction. Maybe that's the trick. I'm stuck in the house waiting for Santa  , once he comes we're taking a 100 miles trip perfect to test if disabling the speed correction did anything

One thing I never searched if the correction is + 3mph or +5%


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## shawnsheridan (Jan 10, 2009)

dromader said:


> In another thread recently somebody enabled the digital speedometer in addition to disabling the speed correction. Maybe that's the trick. I'm stuck in the house waiting for Santa  , once he comes we're taking a 100 miles trip perfect to test if disabling the speed correction did anything
> 
> One thing I never searched if the correction is + 3mph or +5%


On the E60 you had both as follows:

BC_V_KORREKTUR = Correction for Analog speed 
BC_DIGITAL_V_KORREKTUR = Correction for digital speed

BMW can advance the speedometer by 10% + 2.4 MPH per the attachment, which at higher speeds can be pretty substantial. 90 MPH could read as high as 101 MPH. :yikes:


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## johntomferg (Dec 25, 2012)

I'm at the same point (2013 M5).

SpeedometerS are at 74 when going 70.
Adjusting the one BC_V_KORREKTUR key that I found had no effect.

Could not find any others that seemed relevant.

Moving to a 295/35 on the rear is enough to offset the 4% but would prefer a software solution as opposed to hardware purchase.


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## johntomferg (Dec 25, 2012)

Anyone have any success with the F10 M5 and speed correction? Shawn?


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## shawnsheridan (Jan 10, 2009)

johntomferg said:


> Anyone have any success with the F10 M5 and speed correction? Shawn?


Sorry, I don't have a working solution.


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## johntomferg (Dec 25, 2012)

Shawn,

I sincerely appreciate your reply. 

 

With the multitude of forums and posts on coding, the direct response is the only way I could be sure that I hadn't just overlooked available information. I think what you and the rest are doing with the coding is "great", please keep it up.


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## shawnsheridan (Jan 10, 2009)

johntomferg said:


> Shawn,
> 
> I sincerely appreciate your reply.
> 
> ...


No problem. I wish it was something we had solved though.


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## v3n0m (Mar 3, 2014)

Hey all, update on this. Not sure if it helps anyone out, but on my F10 M5, secret menu, I noticed that I can see the "real" speed.

http://f10.m5post.com/forums/showthread.php?t=939218

Under "Speedo/Rev":
v CAN = the "real" speed
v pointer = the "adjusted" speed

See attached photo.

Anyone know how we can make the digital dash use the value shown in v CAN?


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