Ever since the early 1990s cars have been built with a special safety system called a park-brake interlock system. This system is one of the most common causes for a vehicle to stop shifting and be stuck in park. Another possible cause for your vehicle to stop shifting is that liquid has spilled inside the gear shift. If your Mercedes-Benz C320 will not shift out of park these steps will help you avoid calling the tow truck.
Put your foot on the brake and attempt to move the gear shift out of park. The park-brake interlock system will not allow you to move your car's shift stick into position unless your foot is on the brake. By applying the brake you will be able to shift freely.
Remove the console covering the shifter. The console can be easily removed to check for other problems if applying the brake does not work. The Mercedes-Benz has cupholders near the base of the transmission shift stick. If spilled liquid enters the shifting console it can stop it from functioning.
Use a clean cloth soaked in an alcohol solution to clean the inside of the stick shift. Make sure you remove any residue that might be causing the issue.
Locate the safety override button near the base of the shifter mechanism if these solutions fail to fix the problem. Pushing this button will override the park brake interlock system and allow you to drive your car to be serviced. If you need to resort to this step it is likely that the solenoid or cable mechanism is broken and needs repair.
