The safety recall is scheduled to begin in September.
The recall involves 2000-2002 M-class and 2000-2004 M-class AMG vehicles, the National Highway Traffic Safety Administration said in a statement.
The statement said drivers could have difficulty disengaging the cruise-control mechanism when pressing on the brake pedal -- one of several options for turning off the cruise control.
"Specifically, where the driver pumps the brakes rather than applying consistent pedal force, the level of force required [to disengage the cruise control] may be unusually high," the NHTSA said.
Dealers are expected to fix the problem free of charge.
Consumers can call Mercedes-Benz at 1-800-367-6372 for information.