Battery discharge... PLEASE HELP!!!

[Dynamic213]

Hey everyone, I have an 2002 A4 1.8T Quattro with 55,000 miles.

The problem first started when I left my car parked for over a week. Tried to start it one cold morning, and the car made some clicking noise and would not fire up. The interior lights were going dim and it was an obvious battery problem. So I got it jump started and took it to the shop. I installed a brand new battery and had the alternator checked out. The alternator was pushing strong so it wasn't the problem.

Initially I thought the problem was fixed with the new battery, but about a week later, the battery was completely drained again! This time I took the car to my local shop to see if it's something else. They tried to work on it for over a week looking at any possible drainage but could not find anything since they didn't have the proper Audi tools to test.

So with no choice I took my car to the actual Audi dealership. They checked my entire electrical system and said that the car's central computer thought the car had an automatic transmission, but it was a 5 speed. So whenever the car is off, the computer keeped searching for the transmission relay. They reset the computer and that seemed to fix the problem for a little while. They keeped it for a few more days just to make sure... and guess what? The battery was drained again! They then rechecked my electrical switches, wires, relay boxes and still could not figure out the problem. They said they're going to contact the Audi field service manager and see if he knows anything about it, but so far he hasn't gotten back to the dealership. My car has been sitting there for over 3 weeks now with no definite answer to the electrical drainage proble.

Have anyone ever had this problem before? I'm pretty upset because no one is able to figure out exactly what the problem is and I've spent over $500 on repair cost so far with the Audi mechanics scratching their head with no clue how to fix it.

[Dynamic213]

It's almost been a week since I got my car back and no dead battery yet. But have this happened to anyone?

[trautob]

No, I've never heard of an audi changing its mind with what transmission it has.

[blubyu]

Ive got the same problem right now with my car. It only happens when it is cold but the battery goes dead as a nail. I have checked the alternator which is still good, did a draw test when the car is off and there is very little.

[PS8boost]

mine died after +150 miles from the day i drove it out the dlrs. parking lot, thanks to warranty. But seems like a common problem for A4's.

[bojacks]

here is some good advice i found about a A4 diesel with your same problem.

Ask the dealer (or a competent auto electrician) to check for battery drain when the car is left as it would be at the airport. The alarm, clock and some of the computers all drain a little charge from the battery, but it should be no more than about 0.05 amps in total. This is not enough to discharge the battery over a couple of weeks if it’s in good condition and fully charged to start with. If it’s more, check each circuit in turn by removing the fuses until the drain reduces, then investigate the culprit. If you only use the car occasionally – and if you drive to the airport at night – it’s possible the battery isn’t fully charged when you leave the car, which could be part of the problem.

Source : http://driving.timesonline.co.uk/art...181721,00.html

[needforsleep]

I had this happen to me too, but after I had the Optima Red Top put on a trickle charger for a 24hr period the car has been fine. BUT, the question is WHY did the battery die in the first place? This is the 2nd time my battery has died for no apparent reason. I don't EVER leave my lights on, I never leave any interior lights on.

The ONLY thing I've been able to narrow it down to is a bad door contact switch which may cause the car to think the door is still open and keep the interior lights on and other modules awake on the vehicle bus.

I've not proven this but so far the Dealership has looked at the car once and found no electrical system issues.

[darkstar]

i had this same problem it would take about amonth for it to die i changed the batter 2 times it has been fine since then...

[B6driver]

this is crazy... ive never heard of a car having an identity crisis... our cars are way too cpu dependent. in a way its good, such that they are easily tuned through the odb ports, but then theres too much dependency on it.

[Dynamic213]

here is some good advice i found about a A4 diesel with your same problem.

Ask the dealer (or a competent auto electrician) to check for battery drain when the car is left as it would be at the airport. The alarm, clock and some of the computers all drain a little charge from the battery, but it should be no more than about 0.05 amps in total. This is not enough to discharge the battery over a couple of weeks if it’s in good condition and fully charged to start with. If it’s more, check each circuit in turn by removing the fuses until the drain reduces, then investigate the culprit. If you only use the car occasionally – and if you drive to the airport at night – it’s possible the battery isn’t fully charged when you leave the car, which could be part of the problem.

Source : http://driving.timesonline.co.uk/art...181721,00.html

Thanks for the link! So I guess the easiest solution would be to purchase a portable battery starter.

[Dynamic213]

Sorry to keep drilling at this topic, but I'm getting pretty fed up with this battery drainage problem.

Having to pop my hood and pull out my 40lbs industrial battery starter just to start the car every time I drive is just f%&*ed up! It's not just early in the morning I have to do this, I have to do this EVERY SINGLE TIME! Before going to lunch, before heading home from work, before going to the grocery store, leaving the grocery store parking lot.

I decided to contact Audi America and filed a complaint about this problem since I wasn't the only one who's experiencing this. They called me back the next day and told me they're going to contact my local Audi dealership and have a regional technical field manager to look into the problem. They're planning on studying the entire B6 A4 electrical diagram according to Audi.

So far I haven't heard anything from the dealer as of yet. Hoping they'd get back to me with an answer of some kind other than "Sorry, there's nothing more we can do, you're f%&*ed."

If they don't fix this then I have no choice but to trade it in for something else that's a little more reliable... maybe a Subaru WRX.

[Audi body]

Did you ever figure it out?

[old guy]

Did you ever figure it out?

I don't think you will get an answer from Dynamic. His last post was in 2008....

[customa4]

Last login date is in 2008. I can only guess you'll be waiting a while for OP to respond.

Lol! OG beat me to it!

[Audi body]

Yeah I didn't check lol. Definitely need to pay attention to that!

[Jflow23]

When you arm the alarm, does it chirp? Do all the doors lock? I had a battery drainage problem on my A4, turns out the passenger door wiring shorted. The passenger door would not always lock when the alarm was armed...killed the battery every weekend until I fixed the short.

[diagnosticator]

This problem is usually caused by parking the car a long time and not driving enough or frequently enough, to keep the battery fully charged up. There are several electronic devices that pull a small amount of power all the time, and if the car is not driven frequently enough, the battery will get discharged.

[pimpbot]

I'm having this issue as well on my 2007 A4 Avant MT6. I have to hook the battery up to a 5A charger while at work, then I'm fine for a few days.

I use my Fluke clamp DC ammeter around the negative cable to read idle amps. When I first shut the car off, it draws like 1.2A (with all lights off, 1.8A with footwell and door lights on) for around 10 minutes, then backs off to 0.2 amps.... which is a lot for a battery to sustain for a whole day. I pulled every fuse, and as far as I can tell, it's nothing powered through the fuse block that's causing this drain. I've been leaving my interior lights off until I narrow this down. I also have a trailer light control module that I have disconnected.

My battery seems to hover around 12.1 volts with every thing turned off in the morning, and usually it barely has enough energy to turn the motor over when I start it. Sometimes, it doesn't. I got in the habit of parking the car on a downhill so I can push start it with gravity.

The alternator seems to be putting out 13.4v-13.8v when running (depending on condition of the battery) so I think it's charging fine as long as I'm driving. Unfortunately, I can't get my clamp around the alternator lead to test if it's backfeeding through a bad diode. My 96 GTi had a bad diode in the alternator. It made the motor sound very labored when idling. I don't sense that here, but I could be wrong.

What else can I do to prove it's the alternator? I hate to go through the hassle and expense of removing it if it's something else.

*sigh* I may just have to park with my negative battery cable disconnected.

[pimpbot]

I think I finally figured it out!!

Busted Glove Box

Wut?!?

Yeah, so my hinge was busted. It turns out that the busted hinge was keeping the glove box switch from clicking off when closed, so the glove box light was always on. I saw a reference to this somewhere, so I thought I would try it. I put my iPhone on video record and stuck it in the glove box, closed the lid. I took my phone out, saw the vid, and found that the light wasn't switching off when the door closed.

So, I just pulled the light off the connector and retested the current draw. 1.2A for 30 seconds, then less than 0.1A (which is as low as my Fluke meter reads)!! Yay! Also, it turns out that the glove box light isn't on a fuse, or any fuse I could find when doing the fuse test. I gotta look at the diagram to figure that one out.

Dang, and here I was about to blindly drop coin on an alternator, thinking it was a bad diode or something.

So great! Now I can have interior lights again, and stop push starting my car down the hill.


Now, I gotta do the glove box hinge fix, and maybe a switch replacement.