NikC

Hey all,
I own a 2001 Audi A6 Quattro (2.7L) which I've owned about 5 months now, and it hasn't given me any prior issues and is completely stock. Before work about a week ago I noticed my Key Fob no longer was functioning, so I unlocked it manually, and upon sitting down in it, the alarm went off, and after about 1 minute it stopped. I then drove it about 2 miles to work, and after my shift it did the same thing; no fob connection, and alarm on start up for about 1 minute. I replaced the batteries in the fob and the car still wont sync to the fob, so I would just quickly disconnect the ground terminal on the battery to disable it. I could then get in and start it without the alarm sounding, unless, weirdly, I opened the trunk. If I open the trunk it would reset and I'd have to disconnect the battery again. Now a week later, I was driving and the interior lights randomly came on and the alarm sounded, and so I pulled the ground and all was well again, the next morning however, the car will not turn over. It cranks but does not turn over, what could be happening?? Is it locked in some kind of Security mode? Is it unrelated?

georgeb944

Your alarm will not keep the starter from turning over the engine. Check your battery, grounds, and starter. It could also be your ignition switch.

The alarm fault that you have should be diagnosed by someone with VCDS.

NikC

I threw a brand new battery in and still no dice, interior electronics/lights etc aren’t dimming or in poor shape, so as far as voltage goes it seems spot on. At this point I’ve guessed fuel pump? I replaced the relay and that didn’t change anything so I’ve been thinking about making a trip to Autozone and grabbing a new fuel pump. Are fuel pumps failing without any prior warning signs a pretty common thing on these cars?

meternerd

When you say "won't turn over", most think you're saying it won't "crank". I think you're saying it won't "Start". Battery, connections, etc. probably will have nothing to do with your problem. Will the key fob still unlock and lock the doors? Sounds like you have a problem with your key and the security system. If you have no access the VCDS, you may have to take it to an indy shop or the dealer to sort it out. I'm not really up to speed on the "immobilizer" but it's there to do just what yours is doing....keeping somebody from stealing your car. Normally, if you set off the alarm, you have to reset it by pushing the unlock button on the key fob. Failure to do so may disable the car.

NikC

Exactly, I turn the key and it cranks but won’t start. If it was a security thing I would think it would just lock me out completely and not even begin the start up process, which is what lead me to think fuel pump but I may be wrong..

georgeb944

Based on your prior unresolved problems with the unlocking system, I would guess that your no start problem is caused by that same alarm system.

You will still need a scan with a VCDS to diagnose the problem.

clancy

You could have two separate problems, or they might be related. I also have a 2001 A6 2.7 but have fortunately never had any issues like this. In fact, I've owned the car nearly 10 years and not even replaced the battery in the fob. So I am not experienced in fob issues. My car has the immobilizer so I assume yours has one as well. My understanding is if the immobilizer is not seeing the correct key then the car starts but only runs for a few seconds and the immobilizer shuts down the car. If this is correct then you have 2 issues. One is the fob and related alarms and two is not starting and running.

I suggest you confirm how the immobilizer works and what it does if it does not like the key and/or fob for some reason. And, whether a key that previously worked in the car but later loses its sync with the car can indeed keep the car from even starting. Or, just resolve the key fob sync issue and see if the car then starts. If you start throwing parts like a fuel pump at the no start issue and don't solve the fob sync issue first then you may be wasting money on unneeded parts.