I have a 2004 A4 3.0 Audi that I got about 3 months ago. It's been working fine up until now. I left it parked on Thursday of last week outside my house as I went out of city for the weekend. When I came back yesterday and tried to start the car it would refuse to start (the lights come on, the car makes the starting noise, but dies after a second). This happened about 3-4 times, I walked out of the car, tried the radio (it wouldn't turn on), then decided to try the ignition one last time. This time the car started. After it started, one of my warning lights came on (it's a yellow exclamation mark inside a triangle (like the title icon for this post) with an arrow forming a circle around it). I have no idea what that light means since I didn't get the car manual with my car, and my friend's 2005 A4 manual doesn't have that icon in it. The light went away after a couple minutes of driving.

At first I thought this was a problem due to something overheating or inactive in the car for an extended time (if it was the alternator, I figure the car wouldn't start at all). I had no problems starting the car after 30 minutes of inactivity later in the day. So I thought the problem was gone. Today in the morning I had the same exact problem (this time the car started after 2 tries, and the same light went on again for a minute or so). I don't think it's an overheating issue anymore since it now happened at 7 in the morning, when the weather was a bit chilly. Once the car starts, it runs fine, except the radio seems to be resetting to off (and to FM once turned on). The radio dying like that suggests a problem with the alternator, but there is nothing leeching juice from it when the car is off. Anyone can suggest what the problem is? Thanks.

 

After searching the forums I decided to test the starter, MAF, and the throttle body. Today the car started on the first attempt from an overnight cold-start, although it did make the "barely-starting" noise for about half a second. I intentionally turned my lights on when starting to test if it's an alternator problem. Indeed, they dimmed a little (although the car also started on first try). Now I'm guessing it could be my battery slowly getting drained when the car isn't on. Since I installed an iPod interface a couple weeks ago, I'm starting to wonder if that's the culprit. The only thing that's iffy about the installation is the ground that I wrapped around the ground from another radio connector. I'm wondering if that ground wire is slightly touching another wire. So my question to the radio gurus is "Is it possible to short a wire in the radio connection in such a way that the radio/CD works fine, yet the connection keeps draining the battery even when the radio is off?"

 

The light you are referring to is your ESP light. You should have a button above the radio that reads "ESP" Electronic Stability Program is what it stands for.. its your traction control. It is somehow directly tied into the MAF and if the MAF goes it turns off.
From what you have described with the problems, it sounds like your MAF is getting ready to go. The starting up for a second and then dying is probably related from inaccurate air flow readings. So the computer cant figure out how much fuel to add etc.

 

Thanks, I searched through all the guides I could find and none of them mentioned that warning light. Really wanted to know what the light meant. Wouldn't a MAF problem trigger the "check engine light" though? On my old car it did, ended up paying $1000 for repairs at the stealership, and it was just a Nissan. I guess I'm looking at $2000-$3000 in repairs for an Audi if it really is the MAF. There goes my tax refund. I'm just confused why the car isn't throwing any check engine codes. Also, today I noticed that my clock got reset too, not just the radio. Are you sure it's MAF and not a vampire current? The problem didn't occur until now (about a week after I installed the iPod interface), and the clock + radio resetting suggest lack of juice in the battery. I also had my car parked for over a week about a month ago when I went on a business trip, and the problem didn't occur then (prior to iPod installation). I've rewired the ground to the car chassis today, will see if that helps tomorrow. Don't want to go and throw money away on a MAF just yet if it could be the iPod.

 

No, not always will the MAF trigger a CEL. But it can and will turn on the ESP light if its not functioning or plugged in. MAF can range from $80-$120 and Is easy to replace yourself. It is right next to the airbox. If you need any details feel free to PM, email, or ask me.