How to replace Parking Brake Wiring Harnesses?
 

Brought my 05 A6 into the dealer today because my Parking Brake Malfunction light was on. They called and stated that there was corrosion in the harnesses, which is common, and they both needed to be replaced to the tune of $1,239. Apparently it's a bit of work, with a specified 8 hours of labor.

Anyways, I think I would light the car on fire before I dropped that much money into it for something that I have never used, especially when the parking brake still works properly and the only annoyance is the light on the dash.

Does anyone have a how-to for replacing this harness that they could share with me? I will tackle it myself over the weekend.

Thanks in advance.

Well - I am not 100% sure if the wiring harness is really your problem. I had the same issue when an indy replaced my rear pads. The PB worked (engaged/disengaged) - but the P with a slash appeared on the dash. This was just months after the dealer had replaced the PB control module (before software update was failing when they were doing it for a TSB). The indy guy said he removed the battery overnight and let it discharge. Next day the error was gone.

Thanks for the idea. I thought there were downsides to disconnecting the battery? Or am I wrong?

Can anyone reply to this persons concern about disconnecting a battery to a 2005 - 2006 A6 or A8 Audi? Will that do any harm to the MMI or cause extra work and cost resetting stuff or reconfiguring the MMI or any other part of the car?

I was quoted 285 euro per cable from the park brake module. its less than 2 feet long, shocked

I own a 2006 A8L and have had the yellow Parking brake warning light malfunction with the circle and line through it and have had this light for 10 minths now. I have not touched my emergency parking brake since the light came on because I read that on parking barkes may engage and then be stuck on where you literally have to tow the car to the dealer for repair. So I left them alone. Is there any truth to that?

So I took the car to Burlington ON Audi and after 3 hours (!!!)(they did knock off one hour of labor thank heavens but still leaves two hours at $125.00 per hour to locate the problem ONLY) so to continue after three hours of diagnostics and searching they determined that my wiring harness between the body and the brake assembly (part#4EO 927 904 F) requires replacement. They are quoting $330.00 installed for the wiring harness replacement. I assume that is for the part and labor to install.

So guys my questions are: Does anyone know if this requires special equipment that an Audi dealer may posess or could an individual or a mechanic at a regular garage install this easily enough? Does anyone have first hand experience with these questions?

Thanks so much guys!!!!!!

The part is 4E0927904F. Listed at $230; $170 online price. Has anyone done this yet?!

Harness part numbers are:

left harness: 4f0972253L
right harness: 4f0972254F

I think that's a myth. I know my 06 A8 had the battery go dead and removed for a few days after a guy backed into my front end and after I got a new battery everything worked fine. But for me the parking error still exists.
But an Indy mechanic did say that for some warning faults, if you believe them to be errors, buy an old style test light.....the ones with a bulb. Not the digital ones. Disconnect the battery terminals and attach each terminal on each end of the test light leads. Leave it for I think he said 5 hours minimum but even better overnight. The small test light Bulb will drain the capacitors which store power and that will provide a true reset after completed. My Mmi was not affected. And my settings were all still stored.

Hi,

Just changed my harness today due to complete wiring failure (the wires had corroded so much they fell out of the connector when i was taking it off). It should take you up to 2 hours:
(My car's a late 2004 C6 3.0 TDI Quattro, Saloon, regular suspension)

I used this handy video for reference ->
Tools:
* Phillips screwdriver for the storage belt buckles (no idea how they are called actually... the four shiny things on the floor of the trunk, two on each side) + 10mm socket for removing plastic molding in trunk
* Torx screwdriver/bits needed for removing the wheel well liner
* Soldering iron for the wires + some heat shrink/electrical insulation tape
* A new harness

1. Remove (partially, pull to the side as per the video) the trunk carpeting on the side you're going to be doing (i found it easier to get it done before the i jacked the car up). Once you pull it to the side you'll be able to see where the harness goes in the car and connects to the main loom. Be careful with the plastic clips holding the plastic molding/carpeting... i broke two and i was super careful :(

2. Jack the car up and put on axle stand if possible, remove wheel, wheel well liner (you could power wash it first so you don't get dirty and it will also be easier to find all the torx screws holding it in place)

3. Unclip all connectors (EPB motor and Wheel speed sensor in my case), remove two plastic clips securing the harness to the suspension arm (by pulling/sliding them straight towards the brake caliper) and maneuver the harness from behind the brake line (be extra careful there) so it's ready to be pulled out.

4. Cut the wires on the inside (in my case - epb cables + speed sensor wires) - leave as much as possible of the old harness so you have room for error when soldering/cutting.

5. Pull the old harness on the outside taking off the rubber weather seal as well.

6. Maneuver the new harness in place (outside) and run the cables inside making sure that the weather seal fits snug. Solder the wires on the inside and insulate them well before attaching the connectors on the outside. Attach all retaining clips, refit well liner, trunk carpets, plastic moulding, wheel back on... and you should be done :) cycle the EPB on and off a few times to make sure everything's good.

It might be a good idea to disconnect the battery but i personally chose not to. If you cut wires one at time and you take the time to ensure no wires touch each other/any grounding points i believe there should be no need to disconnect the battery for this operation. Just remember to observe the cable colors, solder first and attach the connectors second.

Hope this helps. Dealership here wanted 75 Euro (100-ish US$) for the harness and 70 for the fitting...