One problem related to cruise control has been reported for the 2015 Mercedes Benz C300. The most recently reported issues are listed below.
On February 9th, during my morning commute on the interstate the car lost power to the drivetrain. Message that displays was "collision assist plus inoperative" along with cruise control inoperative. With an amber esp light illuminated, there was no engine light on. When this message appeared the car would no longer accelerate (limp mode). In avoidance to being in a rear end collision I quickly pulled over, turned off the car and turned back on. Inoperative message, limp mode and esp light was cleared. I called dealer to notify. My thought was the battery is a dud (was replaced the day prior), the car needs a software reboot due to the new battery or car was not connected to the "memory saver" correctly. Or the sensors were dirty. So I did the easiest. I washed the car. This problem continued to happen 5-6 times more over the next few days stalling on the freeway at 65-75 mph. Extremely dangerous & life threatening. No engine problems apparent. Seems to be radar or software. This is extremely dangerous while on the highway, I found many other with this same issue on NHTSA. I attached a picture of car showing message with no power. My seatbelt was off as I was on side of road trying to get to gas station. This issue is cleared by turning car on / off. Then it happens again hours or a day later, loss of power at highway speeds. Coast over.
| Vehicle Speed Control problems | |
| Cruise Control problems |