I hardly believe it - my (our) cruise control is running again ! For a year (yes, A beaten year) I got involved in this project, constantly annoyed you with my stories and setbacks, and since yesterday - things have been going on.
I'll definitely write a cruise FAQ if there's a little more time, but I don't want to keep you from the puzzle solution in short form (including career):
So, April 2003 V8 bought, 4.2 liters, 240tkm back then (today 265). Yes, "clearly, the cruise is going", it was said - since my first V8 had one, but he never left (everything tried, everything OK, yet he didn't go - now I know why too).
First the symptoms: Sometimes he goes, sometimes he doesn't go, when he goes, he goes properly (also speed up etc.), but always switches off by himself after a few seconds to minutes.
So, with the circuit diagram and the error search program, in the order:
Brake pedal switch checked - OK
Pressure circuit checked - OK
All the lines are closed. Guide examined (cleaning) - OK
Pump relays tested - OK
Pump tested - OK
Gas train - OK
All right, I didn't give up. So I went shopping
:complete steering stick new - did nothing
Pump new - did nothing
Brake pedal switch new - did nothing
New vacuum box - didn't work
.... to despair. What does common sense say to you? Of course, the ECU. Tjo, so:
Control unit of an S4 (goes) - did nothing (was not at all done). I had the control unit checked, double and triple (electronic), the thing works (i.e. cables and capacitors as well as resistors OK, chip not verifiable).
... there was something else - of course, the speedometer signal. Tacho signal cable tracked, measured - OK
... As we all know, climate, cruise control and gamma hang on the same blue-white wire, and that is fed by BC. Well, anyway, he had passage (and was just hanging from the climate and the cruise control, not a radio).So again everything measured (perhaps a wackler) - no, all paletti. Entnerft I order a new control unit for a 4.2 for 50 at a stupid dog from the Black Forest. - (Until then, I had about a quarter of my life. 150.- invests in the undertaking). I didn't get it until today, 10 months ago, after months of calling and begging, I had no nerve.
I kind of gave it up. In spring I meet Kristjan from Wiener Neustadt, who sells me a 4.2 ECU from a butcher for a few Euros - somehow it could only be that, so brilliantly built-in - and ... NOTHING I didn't even get any more. Who has counted ? Right, ECU number three.
I was done with this sh. Cruise cruises. I'm not sure if he's gonna kick his ass. Yesterday the Jochem arrives with an S6-GRA control unit (yes, up to an estimated 97/98 the things still had underpressure, I suppose also applies to the A8 and S8). I'm tired of putting this thing in my place, just for rehearsal purposes... And go on the ride (now the dashboard is a walk)
.... and see there - this thing goes PERFECT. And even more ingenious: It has the "extended" functions of my brother's S8, in other words, it can speed up AND brake over the lever (it brakes instead of speeding up via FIX, and it accelerates via REVIEW - very quickly !). The control unit has the same mounts as the V8, looks the same, and functions like first cream.
To put the crown on all this: The Jochem of course not only bought the thing for fun, no, its cruise in 4.2 (almost the same construction month, 80tkm less) makes exactly the same problems as mine. Today we have also changed it with him - and you hardly believe it, even those his problems have disappeared (smallness with the resumption still, but then we tap very strongly on the steering stick lever, because he otherwise regulates 1A and always goes in immediately).
So, long speech short meaning - if your 4.2er spins off with the cruise control (or. a revised 3.6, i.e. a new climate), then by no means buys a used V8/S4 whatever from the same year of construction. Take a control unit that is significantly younger, after 1995 or so, with 12 Poles. This can do more, is most likely still in order and has at least solved my problems in the end. Why these ECUs all die, I can only explain by the fact that they are exposed to extreme heat fluctuations under the dashboard ...
Thank you for all those who helped me on the long way and maybe there are some of you who have the same mischief with their V8 from the end of 91 - oh, to my knowledge the old ECUs from the 3.6 far longer ...
LG
Bastian
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