What model year Benz is it ?  Does the  C1517-4 fault pertain to the need to complete a calibration procedure or is it another fault that needs to be addressed before a calibration procedure can be performed ? If code is just for a needed calibration, Common sense dictates that there may be certain conditions that need to be met and seen by ECU before it will allow you to do your first rodeo, starting with level area, all tires correctly inflated and sensed, fuel level and battery voltage between certain ranges , the steering angle at zero with steering wheel centered. maybe even parking brake on?