2002 CLK-320 Check Engine Light
 

A coworker has this car. For a while it would come on when the brakes were applied but go off a short time later. Now it's on all the time. The driver info display shows "No Malfunction" and the car is running fine with no apparent issues. Occasionally the sunroof won't close and the windows won't roll all the way up but no other symptoms.
All I know is nothing so I told her I would check with the experts.;) We have no nearby dealer and no indy that I would trust with something that could be complex.
Thanks in advance!

Have the engine computer scanned. Many stores will scan for FREE.
And then post the code.