I have an S40 that I bought and recently this problem with the cruise control started happening. I set it on cruise control twice and it works fine. However the third or fourth time (it varies from trip to trip)I am driving it is like it goes "off" and suddenly I notice that I am coasting. I turn the cruise control on and off again and it does not respond. Does anybody know what is wrong and what the fix could be?

 

They say never to answer a question with a question... What year, engine, turbo, awd, etc. Not that I have an answer either way but others might.

EDIT: A big difference between the older S40's and newer S40's is the Electronic Throttle Control versus the older throttle cable. The ECT has issues when it gets dirty. You can clean it for the price of a new gasket and some elbow grease.