i had also changed out the mech unit myself. i couldnt program it tho.
what i learned with this change, i had some things that would be a problem and what i needed to do.
being mostly hands on with this i was able to experience the technical aspect.
when changing it out, it seems easier for programming a new unit versus a used mech unit. odis seems to have less issues. issue dont all go away but is lessened.
to note; coding must be done by a place that has connection directly to the odis vw system. some business other than the dealership have paid annual subscription for this as they do a lot of vw systems.
my issue is that once its coded with odis it doesnt like it if you have used some personal home coding tool to do some mods on the car. like obd11 or vcds. it will cause some issues. for me it was my second key. odis couldnt link up my second key (which was working before) properly. i only figured it out once i returned some of the coding mods back to the original. odis matchs what it thinks your original vin options should be for your car then uses the same pattern. but when we change it out the coding doesnt align up right.
now i tell you this long winded story cause if there are other things that doesnt lineup then you might get issues. that might be another thing you can look into as well. was it a used unit or do you have coding you changed. used units also have the previous car's coding. i dont know what needs to be done when recoding it to your car but again its something you can look into.
