Just had a look inside my old unit and 2 of the 3 "dodads" (capacitors ;) ) do indeed look "suspicious" at one end and are probably in need of a resolder.

So, if anyone has a cruise control problem and is handy with a soldering iron and delving into the ECU box it's yours for the price of the postage (£2-£3). :D

I'd very happily take that off you hands to fix. My cruise a little intermitent and it would be handy to have on the shelf in case I found myself going in that area. I have the necessary soldering qualifications :)

Please PM me if you still have it.

Yes, I've got it, not the sort of thing I throw away! +++
This thread has good illustrations of the repair (ignore that it's about an A6 - it's the exact same unit): http://forums.audiworld.com/showthread.php?t=1728645

The board itself is a very tight fit sliding into slots on either side of the casing - obvious once you pull the end cover off.
I found that squeezing the top and bottom of the casing firmly between fingers and thumb (I put my thumb on the centre of mounting bracket) just bowed the sides out very slightly, but enough to let the board slide in and out easily. ;)

Looking again at the soldering I'd say all 3 (2 for definite) have one terminal that looks "different" so is suspect, but redoing all 6 is advisable.

I'll just wait until the weekend to see if there's any other interest before sending a pm.

I'm in South Bucks, but believe you're in Essex. I'm not going that way in the foreseable future. Are you likely to be near me?

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On a tenuously-related note I heard some woman on Radio 4 this morning describing how she liked walking along the Yorkshire coast near Scarborough. Saying that what made it unusual was seeing the sea, as she came from "landlocked Essex". :Confused:

Old control box sent to Graynada (who isn't in Essex, no idea why I thought that :o ) so no longer available.

Replacement (bought from A8parts) working perfectly. :D

Interesting, the cruise on my FL S8 is definitely a bit iffy and that seems to be the commonest symptom.
It worked fine on the test drive and bringing the car home.

Then in the very cold weather it hardly ever worked.
Now it's bit warmer it's in part-time mode and any operation of the speed change (up or down) can cause it to drop out.

I guess I'll be out tomorrow to attack the switch with the cleaning fluid......... :-(
(no box to change on this one)

I purchased a new stalk from Audi about 2 years ago and changed it. And it was dropping out when trying to increase speed from day one. I figured out it only drops out when I push it completely to leftmost position. If I push it just a bit it works fine.

So when you push it right its OK, and if you left it its not

No. When I push (or push-and-hold) left, which means increase speed, it will drop off if I push it fully left. If I push (or push-and-hold) left just a bit, not fully left, then it will work tip top.

Well having given mine a good clean and a good "thrashing" it's now consistently part-working. :(
Just about useable, but annoying. :-(

The "set" button on the end is now working, almost all the time, both for setting speed and reducing it. :)

Touching the slide switch turns cruise off. :mad:
Doesn't matter how hard/softly or how much or in which direction, so there's no way of increasing speed in increments. You have to accelerate and press "set" which is a tad annoying but not a major hardship I guess. Grates though. :-(

Very odd. This morning I indulged my cruise stalk with some serious "substance abuse" - well loads of WD40 and a good thrashing. :eek:

It then started working perfectly! Drove a couple of miles and every function worked as it should (except possibly the "resume"). +++

Stopped briefly (delivering some stuff) and got back in the car, tried it when I could and it seemed to set, but then I tried to increase speed with the slider and it dropped out. :( After that it wouldn't work at all. :Confused:

No opportunity to stop the car before getting home in case the system needed some sort of reset. More abuse and testing as and when I can.

Edit: been out again (looking at that RS4 http://forum.a8parts.co.uk/showthread.php?t=5963 ) and it's working again.
But the "increase" slider is intermittent and when it stops doing what it should it fails totally until ignition off/on. And the "resume" never seems to work.


Meanwhile any thought from anyone on on these 2 questions:

1. Is anyone aware of the system needing a reset of any sort after a glitch?

2. As I asked (maybe not obviously) earlier in this thread, is there any way of taking apart the switch section without taking it off the car? There are no obvious screws so I'd guess there are covers that can be levered off, or is it all glued?

Has anyone taken one of these off and investigated the faulty one to see what's wrong inside? I would given the chance - anyone want to send me a faulty one? ;)

Tried this again even more brutally today and afterwards it all worked as it should (thoroughly tested, including resume +++ ) for a while.

Then, after doing a speed increase it cut out and refused to do anything, even using the slider to turn it off and back on. :tuttut:
Luckily I was able to stop easily (advanced planning ;) ) and turn the ignition off and on, after which it started behaving again. :Confused:

So are there any further inputs or thought from anyone on these old/revised/renewed questions:

1. Has anyone experienced the CC system needing a reset of any sort after a glitch or have any idea why? (both why glitches and why reset)

2. Is there any way of taking apart the CC switch section without taking it off the car to investigate/adjust/clean the contacts?

Interestingly today it was behaving somewhat better.
Generally working, but occasionally use of "increase" would cause it to drop out, but pressing "set" would get it going again.

So, no need to turn the ignition off today. :Confused:

However the two buttons are physically connected inside the switch (more like blocking each other as you can't operate both at the same time) so I suspect there's something slightly out of alignment inside there.

Mine does very similar things - I generally don't use increase/decrease functions as they're so slow to react anyway. If I want to change the set speed I just adjust as necessary and press set again.

I never have much opportunity to test in day to day use so it's only an infrequent annoyance for me so I've just lived with it as it is.

Just a little update after having the car for about 6 months now.

I use the cruise control regularly and it now works about 98% with no further "abuse" required. :tuttut:
I think the previous owner(s) probably never did use it and as a result the switches were corroded/dirty. Regular use has presumably cleaned them up.

All functions now work 100% except the "increase" slider and "ignition resets" are never required now.
The "increase" function generally works as it should but just occasionally using it will turn off the cruise function, including forgetting the set speed.
But as Adrian E pointed out it's hardly difficult to use your right foot then press "set", which works 100% nowadays. +++