Barty

Car is a 1997 A4. Symptoms: cruise will disengage at times and will not re-engage until car cooled down (next day). Sounds like a classical symptom of some IC/transistor in the module overheating. Has any brave engineer amongst us took the module apart and tried to find out what the culprit is? I am tempted to yank out the module tonigh and at least check for some broken solder joints but I do not expect to find anything blatantly burned out/etc since the cruise still works. Is there maybe a power transistor there that overheats? There ought to be a less expensive way than shelling few hundred bucks for new module.

Man, it seems to be a season for electronics failures in my household. Just the other day my 7-year-old Sony TV bit the dust. I am now spending my evenings replacing broken components in the power supply section. I hope that Audi cruise control will be much simpler :-)

Thanks,
Bart

Shameless in Chicago

Don't forget to check the clutch position sensor. Cruise won't work if it's bad.

hanshy5

I think that's what's wrong with my cruise. How hard is it to replace and what does it cost?

hanshy5

what's the p/n for the clutch position sensor?

David.Norton

that is what usally takes out the power supply. Electronix.com has a good price for the kit of parts that these sets eat.

Barty

I have a HOT and a few misc parts (fusible resistor is shot as well) on order from just these guys. I am glad that what you are saying confirms my findings.
For clariry - we are talking the parts for the TV not the CC.

David.Norton

likes to microcrack, letting the base go open for a bit and the voltage spike from the collector couples though and distroys the transistor. I've been fixing two or three a week, nice bread and butter work.

Barty

I already re-did the solder joints but will have to check for continuity between the output of the tansformer to the base of the HOT like you suggested. I will wiggle the parts and see whether I still get a solid path. What puzzles me that I did not seem to find any burned traces, broken joints etc. But, what I did find that IC is shot - IC601 (labeled conv. out). I do not undestand how these two failures can be related. Anyway, thanks for your help. My parts should arrive today so I hope to have the TV fixed just in time for tomorrow's episode of The Office ;-)

Shameless in Chicago

I don't remeber. Sorry. A couple hundred installed IIRC