I have 1998 A6 Quattro Wagon 2.8L with automatic transmission with 161000 miles. I live in the bay area and use this car primarily for snow trip to Lake Tahoe. About 2 months ago during a heavy snow storm, my car would not shift out of park after filling up at a gas station. After a lot of tinkering I finally looked at the taillight fuse and sure enough it was blown. I changed the fuse and drove the rest of the way home (2.5 hours with no problems). I did some research and learned that it could be bad taillight bulbs. Must admit I neglected to changed the bulbs for about a month and a half and went on many more trips. Then one trip when it was somewhat cold around 38-40 degree we parked the car at the resort and had to move the car a few minutes later and same problem occurred. I had a spare fuse changed and did not have any problems for the rest of the trip. This time after the trip I changed all 4 of the taillight bulbs. The next day I took it back up to Tahoe and it was relatively warm with temps in high-50s. The fuse blew again.

It seems to only happen at higher elevation because I have been driving it around town to reproduce the problem, and no issues.

Do you guys know what is going on? Has anyone else had this or a similar issue?

 

This can be caused by a different bulb on the car going out. I had the same thing happen. My left taillight (LED by the way) kept going. I turn the car off, back on its back. The front left DRL finally went. Replaced it, havent had a problem. Seems like the entire system is hooked in and if something gives the whole voltage it shuts everything off.