I have a 2002 A4 1.8T...My car doesn't start. When I jumped using my wife's car it cranked and started on the second attempt. I unhooked the cables and thought I would let the car recharge itself for a while. About thirty seconds later the car died again. Originally I thought it was just the battery's life being over since I never replaced it (2002 model). It turns out the dealership must have swapped a new one during my coil replacement because the date of the battery says February 2005. Does it sound like I have a more systemic problem than a dead battery? Any ideas what to check? I hate to wind up on the freeway stalled...Thanks

 

From what you describe, I'd suspect the charging system isn't working. Even with a stone dead battery, once the car is jump started it would stay running. Sounds like it ran only as long as the battery had enough voltage from boosting. No charging isn't necessarily a bad alternator either. The field is essentially controlled by the ECM. Best bet is to first charge the battery or jump start it again with a volt meter hooked up and see what it does when the cables are removed. Should show at least 13 volts at idle. Let us know what you find.

 

Agreed with aspen79, that happened to a Subaru of mine, I replaced the alternator after the guy at the battery shop said it wasn't charging, and then it turns out that the alternators signal wire from the engine wasn't telling the alternator that the engine was on, so the alternator never activated. That car had massive problems, that was just one of them, but the moral is, it may not be your alternator (as aspen79 said).

 

Thanks, I went ahead and replaced the battery and it is working fine...I bought a voltage check gadget to make sure. I live in Houston so batteries don't last long in the heat so I've been told.

 

Hey im having a simular problem, what voltage did the alternator show after...

 

This thread is over 2 years old. In his case the battery was the problem because he needed to jumpstart the vehicle. Audis are very finicky, and if the battery is not working properly, all kinds of weird issues are going to come up.