i keep get CEL because the battery too low..replaced the new battery still have the cel...lol
my question is how to reset the ecu...
i disconnect the (-) battery for overnight..still cant reset it..

 

Disconnecting didn't work for me either on my 99 2.8. Neither did any combination of drive cycles and miles driven. I had to do it with VagCom.

BTW for future reference - go to your profile page and create a signature with your car's year, engine, transmission, and driveline (quattro or fwd) - it'll help a lot in the future as you post more in-depth questions. There are a lot of things that vary on these cars from model to model, and it'll save you having to tell us each time what your car is, and will save you having a bunch of people asking about it.

 

97 1.8t quattro all stock

 

use a code scanner at autozone if you don't have vagcom.

 

autozone will clear them for free. disconnecting the neg side didn't work for me, but it did for my friend, so i dont know whats up with that.