Bmw 330xi 2004

The diagnostic code will need to be checked, then an opinion can be formed as to what may have occurred. You may be able to have the code checked at a local parts store, some will read them out for no charge. If you can get the code and post it here we should be able to help out.

Once they clear the code, assuming they fix the problem, their is no way to find out what went wrong unless they tell you. The possible problems are not worth considering, making sure they are honest with you is. Ask them for a service record showing you what was replaced or repaired on the car so you can maintain a proper service/repair history.