Distronic SCN Coding
I really wish I didn't have to bother you with the issue I've recently encountered, but right now I could really use some expert help. The car in question is a 2005 W220 S320 CDI 220.025.
Yesterday I got my indy to carry out a distronic retrofit using new parts as described by David Prokity in his famous youtube video. Since my mechanic has also got DAS with developer mode, we decided it would be a good idea to at least test the system by performing offline SCN coding for distronic before I visit the dealer for a data card update i.e. addition of code 219.
The diagnostic equipment recognized the presence of the radar control unit behind the front grille right away and warned that SCN coding was indeed required to make it work. No plug and play stuff, that was kind of clear beforehand. We ticked the distronic boxes in the instrument cluster, CGW, ESP and system diagnosis subsections and coded them. So far so good. But then, as we tried to do the same with the ECU we were greeted by an error message which stated something along the lines of "Error 85xx, unable to read data". The whole SCN code subsection for the ECU was unavailable, not even as read only data. Just a blank screen. Which was odd, since the ECU is definitely functioning properly, no DTCs, it has caused absolutely no problems whatsoever for the 3 years that I've owned the car. After a quick update of the ECU flash firmware with the latest available version, we got the same result.
My indy guessed that the ECU had probably been tampered with by tuners who had locked it afterwards. If that's really the case I would have never guessed that my car had undergone chip tuning at some point of its life. The previous owner certainly never mentioned anything and there is no such entry in the service history. Just great.
Still, the mechanic made an educated guess that online SCN coding at the dealership may still work and bring distronic to life without the need of removing the ECU EEPROM and manually recoding it first (in order to unlock it and generally bring it to stock condition).
So, after this rather lengthy explanation my question to people familiar with this topic would be - is it wise to go ahead and code the car at the dealer or would it be an utter waste of time and money and even possibly cripple the ECU to a degree that the car wouldn't even start anymore? Thank you in advance.
Anyway, I managed to source some of the parts on ebay, because it didn't make much sense to buy them new from the dealer (which is always the least cost effective option, but an option nevertheless). I was lucky enough to get hold of a brand spanking new and unused radar control unit in a sealed OEM box for a fraction of the price at the dealer which actually enabled me to complete this project successfully. The rest of it wasn't much of a problem. I then obtained a used distronic grille, wood panel and interior switches in perfect visual and working condition for next to nothing. Lastly, as I had no choice I was forced to visit my local auto parts store and order the two wiring harnesses.
Since offline SCN coding didn't work for me - hence I started this thread, I did what David Prokity had done and popped over to the dealer to get the components such as ESP, ECU, CGW and Instrument Cluster online SCN coded. I'm happy to report that it did the trick and now I have a fully functioning distronic system on my W220.
Last edited by dido1986; Feb 12, 2017 at 05:58 AM.
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I bought the pieces separately I found the distronic unit new on eBay Germany, the grille and the wood trim/ switches on eBay , the 2 wire harness from the dealer .it was not easy to find them it took time but now it looks like very difficult to find someone to help me with updating my car data card .
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Anyway, I managed to source some of the parts on ebay, because it didn't make much sense to buy them new from the dealer (which is always the least cost effective option, but an option nevertheless). I was lucky enough to get hold of a brand spanking new and unused radar control unit in a sealed OEM box for a fraction of the price at the dealer which actually enabled me to complete this project successfully. The rest of it wasn't much of a problem. I then obtained a used distronic grille, wood panel and interior switches in perfect visual and working condition for next to nothing. Lastly, as I had no choice I was forced to visit my local auto parts store and order the two wiring harnesses.
Since offline SCN coding didn't work for me - hence I started this thread, I did what David Prokity had done and popped over to the dealer to get the components such as ESP, ECU, CGW and Instrument Cluster online SCN coded. I'm happy to report that it did the trick and now I have a fully functioning distronic system on my W220.



