I agree with Mark, need to get the codes pulled for a start. I'm not familiar with the model you have as it is non-US, is it a sister car to one of the American models?
If a shop replaced the IAC, and the cruise stopped working, I would ask them to recheck their work.
Like Mark said, check for a vacuum leak, disconnected or cracked hose maybe, air intake not tight or leaking.
Sunday, November 11th, 2007 AT 5:52 AM