Assuming you are referring to a Park Distance Control (PDC) sensor, also commonly referred to as a parking sensor:
The cost of repairing a PDC sensor will vary depending on the make and model of your vehicle, as well as the severity of the damage. Typically, replacing just the sensor itself will cost between $100 and $200. If the damage is more extensive and requires repairs to wiring or other components, the cost can range from $500 to $1,000.