Any ideas? Any way to fix it?

 

it probably does work but you have to turn it on and then press the button down pretty firmly and let off, try doing it a few times in a row and keep your foot off the gas pedal. i thought mine was broken for the longest time then i finally got it to work. Just keep messing with it

 

Could be a lot of things...vacuum pump, stalk, control module, or brake light switch are all common sources of failure. I got mine to work by removing the module and having someone pass a heat gun across the board to re-wet the solder. It's back to not working again and so my next move is to replace the brake light switch.

 

at least for me, my CC didn't work for a bit because when I was replacing the valve cover gaskets I took off a vacum hose for the CC and that stoped it from working (this is in a 12v V6 mind you) but that might be somewhere to start.


Did it used to work?

 

It's worked twice, both times when I was going 25.

 

Alright, I rana vag com and I got back some "break light switch" error.... What is this brake light?

 

Among other things, it can be a cause of non-functioning cruise. It's attached to the brake pedal. I have that DTC, but the only symptom I have (hopefully!) is the broken cruise control...I guess it's possible that I've had an intermittent problem with my brake lights that I've never noticed. More important than what it actually does is that it's pretty cheap (but very delicate!) to replace . Here's a good DIY:

http://forums.vwvortex.com/zerothread?id=1158315

 

I was under the impression that when you check for codes you will ALWAYS get a brake light switch error unless you press the brakes once after turning the key on. I think I read that somewhere. Ah yes.. here it is... from the ross-tech wiki(Apparently only on tip cars)

But my cruise doesn't work either after cleaning that stalk, and checking the module solder joints so wtf do I know?

Where is the vaccum pump and how do you check it? Could look it up, but it's easier to ask someone who already knows!

 

If that's the case, then how would we ever know when to replace that switch? Its failure is pretty common.

Here's a DIY for testing the various components of the system:

http://forums.audiworld.com/a4/msgs/1273770.phtml

Most people have no success after cleaning the combination switch. That could definitely still be your problem. And when you say you checked your module's solder joints, does that mean you looked at them to make sure there were no visible cracks? Because that's not enough...mine looked absolutely fine, but sure enough, a few passes under a heat gun and it was working like a champ.

I think the vacuum pump is under the ABS unit.

 

Also check diagnostic article http://forums.audiworld.com/a4/msgs/2596840.phtml

I checked everything and mine works occasionally. The SOB has a mind of it's own. Good luck!