WARNING If you have a Bose sound system it may lock (anti-theft) if you disconnect the battery. You need a code supplied by the dealer to unlock it. Most of us who bought a used A6 don't have the code and the dealer will charge you to unlock it. Make sure you keep power to the electrical system if you're disconnecting the battery. Places like Autozone sell a AA battery powered device that plugs into your cigarette lighter for this purpose.

 

One other note I have bought two of these same cars that were flooded from this type of problem and fixed them. once you have the interior control module (located under the carpet in front of drivers front seat) and the transmission controller (located under the carpet in front of passenger front seat) taken care of by either drying them out or replacing them. these are in black plastic boxes and it sounds like they are toast at this point but theres always a chance that drying them out will work.

You will have further problems down the road if you do not check the wiring harness that runs under the carpet along the door sills on both sides of the car. inside this harness they have butt connectors that have a rubber boots on them this boot helps hold in water and the wires will corrode and break at the connector. you will need to remove this boot and soldier and shrink wrap these connections or else you will chase electrical gremlins forever. Also if you have memory seats take a close look at the seat controlers as they hang under the seat and if the water was as deep as you say they probably got water in them too. check right where the wires plug into them as that seems to be where the biggest corrosion problem is.

feel free to pm me if you need more info as to where these connections are I will try to find the pics of the repairs I made.

 

padog, we did dry out the plastic boxes and just recently we turned on the car and all the signals indicating hazards like the abs sign and such went back to normal. We also partially removed the carpet to get to the wiring you were speaking about and dried those out as well, and i will definitely shrink wrap them too. how likely is it that electrical problems will persist? oh, and the power seats are still working. so that seems to be okay. Thank you so much!

 

ppgoal, thanks for the info about the anti-theft lock. I'll tell my dad about that. (as i am a girl that has no experience with cars ha) How much does that cost?

Thanks for the help!

 

Glad to hear you were able to dry things out that saved you a lot!

As for the Harness you need to cut the wrapping and look for the little rubber boots that cover up the crimped butt connectors these boots hold water and will continue to corrode pull them off and tug on the wires they are a very fine gauge wire and will readily break off if there is a problem. If they still seem to be holding firmly then get yourself some dielectric grease which usually can be found at the auto parts or I know home depot has it also and coat these connections with it and put the boot back on. if the wires are corroded and breaking off then cut the butt connector out and soldier and shrink wrap these connections. Also disconnect the battery and remove the plugs for the interior control module and the transmission module inside the black boxes and give them a good coating of the dielectric grease also be sure to cover all the pins. this will help stop the corrosion.

To get to all of the butt connectors in the harness you will need to remove the seats and pull the carpeting back. You will find them inside the harness along the door sills and where the harness runs under the front of the seats there are about four of them along the door sill and two more under the seat on the driver side and I beleive just one under the passenger seat. if you take care of all of these connectors and the plugs on the modules you shouldnt have any further troubles.

Oh and the radio theft code shouldnt be a problem on your 03 it seems that after the 01 model year it doesnt happen very often I have done an 02 and an 03 and had the battery unhooked numerous times and never had the radio go into theft mode but if it does take your vin into the dealer and they can get you the code.

Be sure to pull the battery out and check the drain that is underneath it because many times it is clogged and thats what causes the water to get in the car.

 

Hi All, been having the same problem with my 2001 A6 Quarto. But I think I might have found my problem anyway!

The cable for the Bonnet(Hood) release has a rubber plug where it passes through the body. Mine was pushed in so far I could see the floor inside! So persuading it with a pliers I pulled it out, firstly too far but that actually helped. I could see a groove where this plug sits wrapped around the body of the car so using a long flat screw driver I pushed it back into place.

I've added some photos so you can see what I am talking about.







Should have taken some photos while I had the plug pulled out but thought of it too late
Mines a left hand drive so the cable is on the left but as far as I know on a right hand drive the cable is on the right.

Hope it helps

DwaneD

 

There is a Drain flood damage class-action in progress- check the forum for the web page and for your consideration.

 

Pulled out the module from under the carpet, two wires have have come off the plug and I am not sure which terminals they go to, red with blue stripe is the larger of the two. I am having trouble making out the wiring diagram in the Bentley manual. Following all the other advice given, but this is holding me up.
If there is a better diagram I would love to see it!
Thanks in advance