could be 2 issues, hopefully the cable at the throttle body is a little loose and needs to have some slack taken up, if not it's most likely the cruise control brain that is located under the dash just above where your left knee is when sitting in the drivers seat, not a hard change out but a little time consuming

__________________
Jerry

2004 SL500 Black 55K Miles
2002 s500 Black 90K Miles
1986 300E Gold 233K Miles
1966 Twin Cessna 320D
1989 Jeep Cherokee 233K Miles
1994 Ford Van E150 399K Miles