A new battery in an Audi needs to be programmed to let the vehicle's electrical system know that it has been replaced. This process is known as battery registration, and it resets the charging parameters to account for the new battery. If not the new battery will die prematurely. I checked with 2 Audi service departments and they both said the battery has to be coded.
I have a Carly and that coder doesn’t give me the option for Battery Registration. It does give me the option on my BMW’s but it didn’t on the Audi. I’ll look again.
Must be different in the USA because in Europe you definitely have to register the battery.. sometimes you may also have to reset the one touch window functions after a battery change.
Funny you ask. I think it has a leak at the water pump that I just found. I don’t know for sure but that’s what I suspect. It’s super super slow leak. Other than that I have had zero issues out of this car. Very reliable.
This is a common problem on A4s as the water pump is plastic and they fail prematurely. There are some great YT videos on replacing it but it’s fairly involved. The leak will get worse until the pump fails.
