Good day everyone,
Looking for other ideas or possibilities.
My 08 A8L has the ESP/ABS/Parking brake light come on anywhere from 5-15 miles into driving. I lose speedometer/cruise etc. Trach works. Took it to an audio mechanic who told me to ditch the car because the ABS module is totally dead.
I'm going to clean the connector pins as soon as it's not 110+ outside.
My question is this, is the abs module something that can work but then fail as it gets hot or is it a it works or it doesn't.
Other than checking the contractor pins and wiring is there anything else to check as it seems odd that it works for 5-15 miles then throws codes and suits off Speedo.
Oh also it will throw a speed sensor engine code (save mechanic said it's because of the dead abs module not an actual speed sensor.
(I do not have a scanner to give me all the cool checks and codes everyone posts)
Any ideas or thoughts would be greatly appreciated.

 

Brake light switch. Do a search FFS.

 

I've done multiple searches thank for naming a random part. Everything I've searched says the EPS/ABS/PARKING BRAKE all at once is common wiring harness issue or pin connection at the ABS module. But I'm not familiar with the module to know if it can work sort term then suddenly stop only to work again after parking the car for 5+ hours.
Why would brake light switch cause the other systems to default to off? Little more info would be nice since you seem to know more than I.

 

Could be a bad Brake switch, and/or failing wiring loom insulation. But more likely a failing module. Telltale is the failure appearing once it’s warmed up. Classic electronic failure mode.

The ABS electronic module can be removed from the valve block and sent away for repair easy enough. Plenty of module repair firms out there these days, and plenty of threads on here describing the process. Google is your friend.

 

Ok thanks that's what I needed, the module is failing vs completely dead as advised by mechanic. We're living with it until I can drop a new engine in my mini and have the time to ship it off.
Any companies to steer away from for rebuilding the middle or one that is the go to?

 

I had the same symptoms, tried replacing the brake switch, but it made no difference. I inspected the wiring leading into the connector that fastens to the ABS module, and all wiring looked fine. So I pulled the ABS module and sent it to Module Master in Idaho, they rebuilt/resoldered it, did a great job and all error codes disappeared. One week turnaround time.

 

Note that you can remove and replace/repair the ABS module electronics without removing the hydraulics. I bought a used item with the same part number and coded it and it works perfectly.

 

+1

 

How were you able to get the abs module off without removing everyone around it

 

Loosen and move the coolant and PS fluid reservoirs to give yourself room to work. Disconnect the large plug that connects to the ABS module. My plug did not want to come out and I had to clean years of dirt and gunk off, and work that little clip that holds it to the brake "distribution box" back and forth for a while, slowly, until it operated smoothly. Contact cleaner helps. Otherwise I might have broken the plastic handle. With those two tasks out of the way, you "just" need to remove 6 torx screws that fasten the module to the brake "distribution box." In my case, I also removed the left front wheel and wheel liner to get at one of the screws from a better angle. Also, I carefully bent back the heat shield between the ABS and the engine in a couple of spots so my tools would fit and I could access another one of the screws. Tight quarters in there, for sure, and tools (small ratchets with torx bits) need to be the right size to get in a couple of places, but it can be done. Just work at your own pace and be patient. After all 6 screws are out, carefully pull the module away from the brake box without disturbing the "springy" coils in there. With that module removed I covered the brake box with a plastic bag to prevent potential contamination. It was much easier to reinstall the module - 1 hour total - after having gone through all this to remove it. I'd say I spent 3 hours removing it. If you are interested I think I have a writeup of this that I got from another D3 forum member. Allow 5 working days for the repair, add another couple of days for shipping to Idaho.