good points gilly and donnie. thanks. I will look into the self adaptation and check the wireharnesses. If it isn't good I will have Mercedes replace it under warranty. $500 otherwise.
the problem is that this mechanic is the shops owner...20yrs+. he said he pulled the codes etc. Hence idle control box or unit. He might actually mean the throttle actuator because he said its the box that controls the cruise control etc. You guys feel its the throttle actuator. I'd like to go with you on this one. I read in one of your posts that you have never replaced the control units and that you could see this only if the throttle actuator is faulty and it blew out the computer. You also mentioned that if you replace the controller without the actuator then it will eventually blow too.
so now you see I'm a little worried. He puts in the new unit and a month later the faulty actuator messes it up.
either way it looks like a big job. well now ill be prepared for tommorows showdown!!! I'll keep you all posted...stay tuned