jdman321

I just bought a brand NEW battery thinking it would solve it...the next morning I went out to the car and the buttons on my keys didn't unlock it so I knew it was dead.

The security light was solid red on the driver door. (that has happened every time it was drained).

Last time I drove it to the mechanic he told me the coil pack thing was loose and he put it back in, but the next day it was drained and I got it jump started and it was ROUGH. Extreme shaking while pressing on the gas, even well after warming up while driving it back to the mechanic.

-Flashing CEL on startup but normally corrects itself back to solid.
-Extreme shaking while pressing gas
-Lights and dashboard were flashing and beeping for a few seconds one time after a jump.
-Brand new battery keeps draining every night but jumps fine. (old one drained too, which is why I bought a new battery)

Caseyj955

If I'm reading this right your CEL is on solid after starting and the battery ends up dead overnight, and you have a missfire when trying to accelerate. If this were my car here is what I would do.

Physical inspection, look around under the hood for any loose electrical plugs or vacuum/boost lines. Where I live chipmunks tend to nest under the hood and chew through wires and vac lines to make nests, so anything that doesn't look right.

If the charging system is not doing it's job then the lack of correct voltage could cause drivability issues so I would make sure your car is getting correct voltage before diving into a missfire (beyond getting a code scan, do this first) or any other drivability issues. Did the issue with the battery start right after the mechanic played with the coils? Has it ever happened before or only now that he messed with it? You might drop him a call, a polite request may prompt him to have another look at it. Alternatively you could ask the same parts house that can scan codes if they have a charging system checker, many do and will do a quick check for you as well as a code scan.

Coil packs are a common fail item with these cars so if your mechanic did somethign to coils and the problem was resolved for a short time than that is a good indication that it may be coil related. Not necessarily but there is that likelihood, this is why we need the codes stored in the ECU.

If you get the stored codes from the ECU via a codescan and an idea whats up with your charging system you will have a great jumping off point. Write down any codes that get pulled and what the results of a charging system check turn up and come back here with that info.

I'm new-ish to Audi but been a car guy for several decades, so any seasoned Audi folks please feel free to correct me if I'm off base. If the issue gets resolved please post what it was.

buratino1117

well, I have an 06 B7 2.0 and I had the same issue. I made the mistake of replacing a 2 year old Oreilly battery with one from the dealer. I had to do some work to find where the problem was but in the end I did find it. It was the module that is hiding behind the headlight switch, not far from it. I forgot what the name is but in my car , when I turned the car off , the small lights from the lights switch were staying on. I did measure the current consumption, and to make a long story short, the car was not going asleep properly. The module is expensive from the dealership but for me I found one in a junk yard for $50. is not hard to install and it has about 3 or 4 relays (they are aluminum with green on them- that may help you identify the right module) and also has I think 4 connectors with quite a few wires to it. If your car has the same issue, and the small headlight switch (or possible some other dash lights) I would not be surprised that your problem lies in that module. There is detailed information on line how to measure the amps that are drown before and after going to sleep. Good luck finding the issue, and maybe you can post the outcome.

jdman321

This helps a lot!!! I noticed yesterday that I locked my car and the red lights near the headlight *** was still lit, so I just kept unlocking and locking it until it went away.