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Kombi Module: Coding Real Speed!

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maupineda
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Kombi Module: Coding Real Speed!

Post by maupineda » Mon Jun 15, 2020 5:49 pm

FYI. this is a tread I had started too in the NA forum (ZPOST), but thought it was a good way of me to payback this forum the lots of valuable information I have gotten from here too.

As the title says! I was able to finally code my Kombi module so the speedo reads the real speed.

As some of you familiar with coding there is a parameter in the Kombi module that suggested there is a built-in error in the module, however, changing this parameter from active, to not active, does nothing to correct the speed making us believe that there was no way of fixing this, or at least I could not find a solution up until now.

to the point now...

Reading through the Kombi parameter I found the following ones that gave me a few cues

K_ZAHL_TACHO
K_ZAHL_TACHO_KOMPL
K_ZAHL_WEG
K_ZAHL_WEG_KOMPL

The first two are for the speedo reading, and the other two are for the odometer. it was very odd for me to find they are different when in reality they measure something very similar, so what I did was basically match the values of the first set of values to the other two

Below you can see the original values of all 4 parameters

K_ZAHL_TACHO
4764_imp/km
K_ZAHL_TACHO_KOMPL
4764_imp/km
K_ZAHL_WEG
4716_imp/km
K_ZAHL_WEG_KOMPL
4716_imp/km

So the deltas between the two sets of values made me think that the speedo was forced to read more pulses per km than the odo, making it to read faster than actual, so I matched them and tested...

well... to my surprise the speedo was reporting actually a bit more speed than with the original setting, so I came back and said, well, let's go in the other direction, which I did and went to the max setting available just to make a more drastic change and confirm if I was moving in the right direction, and to my surprise the readout was perfect! pretty much within 1kph of the speed reported by the GPS.

Below are the settings I am using (I did not mess with the odo)

K_ZAHL_TACHO
4961_imp/km
K_ZAHL_TACHO_KOMPL
4961_imp/km
K_ZAHL_WEG
4716_imp/km
K_ZAHL_WEG_KOMPL
4716_imp/km

I also set the speed corrector to not active per below

BC_V_KORREKTUR
nicht_aktiv

The image below shows the different values available in NCSDummy, this image is taken from my original Kombi settings, so you can see what the default values were.

All I did was to change the "TACHO" parameters to the ones indicated above
KombiValues.PNG
KombiValues.PNG (69.95 KiB) Viewed 1235 times
I hope this is helpful to those that have wanted to have the speedo to indicate the real speed.

P.S. if you have a different wheel size, you can calculate a deviation to the nominal value and create your own values in NCSSUmmy to correct your speed even if you are running a different size set.

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