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-   -   VCDS (Vag-Com Diagnostic System) for VW & Skoda - Discussion Thread (https://www.team-bhp.com/forum/technical-stuff/152370-vcds-vag-com-diagnostic-system-vw-skoda-discussion-thread-61.html)

I'm not a VCDS expert but I work for ECU development so I can understand your situation. Even from my own experience in the Slavia I can tell that for the localised control modules VCDS even in it's latest version doesn't really have the correct coding descriptions and adaptation maps. It is using the most relevant info for these ECUS only. In some cases the channels or coding bits do not exist, and in some others they don't cause any change. Hence it has to be considered in a case to case basis.

For example, there is a sound tuning option in the amplifier which is supposed to change the output, but I have changed it back to back and observed closely that there is hardly any difference. Similarly the head unit has a coding bit to select the type from various options and that's just a variant coding string, while those who are into the coding business claim this as a tweak able mod, which again makes no difference :D

Then there is another case where you have a list of adaptations from a similar ECU But when you try to access that channel you get 'channel not available' on the adaptations page.

There is also another issue where some of the coding changes aren't accepted by the controller. So if in your case, you aren't able to see the adaptation for the steering itself, then that would not be there. Generally, manufacturers never change the position of these adaptations and codes and only add new ones in the spare bits. This will avoid confusions in the after sales tools and assembly line. Only when the platform itself changes, you can find more drastic changes. But say within the MQB platform or the PQ platform, there is a high level of commonality in these things.

That said, if Ross Tech can figure out the correct maps for the Indian ECUS, it would be really helpful. The TFT cluster in cars from October are coming with a tacho display in all pages, be it speedo or 3D page too which want there earlier. However there is no adaptation channel found for this nor a coding bit. I am sure this isn't any hardware change or so but not figuring it out on VCDS.

I know what you're talking about man. Used to have a 2011 Polo 1.2 TDI which drove like a dream. After disabling the Straight Ahead Stabilization, I've definitely improved some braking ability and stability. Even changed my front shock absorbers to the 2011 version which improved the driving marginally. But the fact is, VW has made so many changes internally, even in the chassis, the positioning of the rear springs etc that I dont think even by upgrading to all earlier parts, the same level of dynamics can be achieved. But I still have an upgrade to Bilsteins planned in my head sometime in the next year. Hopefully, they should atleast bring the car upto an acceptable level of driving at the worst.

I have already sent a complete detailed scan report of my ECU (Took a whole 15 minutes) to Ross Tech and also received a note of thanks from them for the same. The debug level 2 scan, scans each and every module for each and every possible channel that is or is not available and also details whether the label and map files of a particular module are available or not along with the module complete part number and firmware version of the module. Ross Tech has promised that they will try to update in the next update of VCDS.

Regarding the tweaking of the steering characteristics, Ross Tech has confirmed that the steering characteristic curve feature was available in the first generation of steering modules with some cars having as many as 16 different curves programmed into the module for choosing. The 2nd and 3rd generation modules have this removed and/or the channels have been locked by VW. The newer MQB platform can anyone confirm whether this is available or not?

I guess in the MQB platform modules have again become common with the international versions. as in my Radio Module, the long coding tweaks of changing the sound system to a skoda sound system or Dyna Audio etc isnt accepted. However, it does accept the rear parking optical module tweaks to change the way the interface looks . Options range from VWs most basic stable to as high as the passat, scirocco etc.

I guess the steering assist module itself has been changed in the newer Indian cars which might also explain the reduction in the feel of precision as the earlier cars.

Even the HVAC module on the 2018 cars doesnt have tweaks to adapt the climatronic according to the local weather. However, I guess the MQB cars have this now as I surely remember one Slavia owner claming to have tweaked the HVAC module to Cold Tuning;More air which basically makes the blower speeds more aggressive to achieve the set temps quickly.

I do however remember one Slavia owner (either on Youtube or this forum) claiming to have changed the steering assist to Dynamic for better precision.

I'd love for VW to also go the MG route and give these options on the touchscreen itself. Although, they've gone a long way with the T - Roc having a lot of options tweakable from the touchscreen itself which is otherwise only accessible by VCDS in other cars atleast south of T Roc budget wise.

It's me who did those tweaks. AC tweak works in multiple ways including enabling an option in the infotainment to set AC cooling strength, and so does steering. In the power steering module I can change assistance curve as well as assistance levels from 0-100%. Both of it works. However sound tuning if changed the coding is accepted but no change.

Apart from that, for example in the Cluster I can see a bit for Lap counter which is accepted but no change.

You mean you've the AC config tweakable from the infotainment system directly without VCDS or that you tweaked it via the Radio Module instead of the Auto HVAC Module in VCDS?

Yes, but it cannot change the long coding but instead it temporarily overwrites the value and the AC behavior instantly changes

I would beg to differ on a lot of points but for Starters, here are the HW and SW versions of an Instrument cluster from a Slavia of the first batch of cars sold and the lower pic is from the latest batch that comes with the added Tacho that you are referring to. :)



Clearly, a different hardware revision and a software revision as well. Can VW update the older hardware with latest software? Possible but seems highly unlikely :Frustrati

The reason the hardware revision is different is because the supplier had changed. At my work this is common that we change hardware revision even if there is a minor change(due to supply chain requirements) and software revisions even if the coding is changed. So that doesn't imply that it's not possible to somehow manage this on older variants. At least from my professional experience since these things are my bread and butter from years.

I know you also feel that the sound settings actually make a difference, but it would help to see some evidence for the same.

Yes it "might" be possible to get it working in older variants. But we cannot bank on it especially when there is different hardware. I would love to add it on older cars as well but this peaked my interest so shared it here.

As for the sound settings, my ears are just about average (I'm more of an Eye Doctor ;) ) but I have done back to back playbacks for someone who is a sound engineer and does sound tuning for a living. There is a noticeable difference and same has been confirmed on more than one occasion by multiple people on multiple cars. There are ofcourse objective ways of checking it but they are beyond my scope.

I guess the sound tuning thing needs to be confirmed without telling the person who's doing the listening, that something's been tweaked. And/or by telling him something's been tweaked without actually changing anything. This will eliminate the placebo effect.

@audioholic do you know if the VW ECU engine mapping can be tweaked from the OBD port or whether the ECU first needs a surgical operation? There are companies that claim that if we buy their obd tool, one can simply buy a pre tested map from them and then use their tool to update it to the ECU, whereas a couple of videos I've seen people taking the VW Polo ECU out on a bench, resoldering couple of stuff at PCB level to unlock it and then claiming to be able to write new maps.

@everyone (please no warnings about the DANGERS of ECU engine mapping)

Yes have done that as well, and multiple people have confirmed my findings.

Yes Tuning is very much done through obd port for a lot of ECUs . I had my polo remapped (ECU and TCU) through the obd port but it needs special tools, not the vcds cable. Newer cars usually dont have the security cracked to be able to write the map through obd but a lot of cars can be tuned without taking the ECU out.

Please can someone point me to the source from where I can download the VCDS software? I did check out the VCDS website but didn't want to experiment downloading just any software without knowing about it.
Also, my Octavia is just 2 months old now and all I want to do is just disable the 80kmph and 120kmph chimes. If I do that, will it void my warranty? Thanks

You can download the official VCDS software from Ross Tech website. But do note that your car cannot be tweaked through VCDS as of now. No it doesn't affect the warranty if you do these changes.

Thanks. But why is that so? When would I be able to do that then?