Odd question but what is it that determines what you can/can't tweak with VCDS like CH lights, DRLs etc? My CAN gateway is running a high(ish) revision (high enough to prevent battery drain running a Columbus/Bolero) but I'm guessing its not the gateway. Some kind of controller? The 'convenience' module? And if so, can I retrofit one from a newer car?

Depending upon what you want to change depends upon which module in the car needs looking at.

And there can be quite a few.

Yes you can fit newer modules in most instances fairly easily. But you won't always get full functionality out of them.

Aye, certainly not one magic bullet, I remember a few years ago when I got the towbar wiring coded at an indy auto-electrician and he showed me his box of tricks doing a diagnostic check first. It was checking 23 (yes 23!!) ECUs that make up the car.

 

Good luck swapping all of them out to ensure full compatibility between the modules.........

 

Niall