2010 Nissan Sentra Owner's Manual - Page 173

SERVICING AIR CONDITIONER (if so equipped) The air conditioner system in your NISSAN vehicle is charged with a refrigerant designed with the environment in mind. This refrigerant does not harm the earth's ozone layer. Special charging equipment and lubricant is required when servicing your NISSAN air conditioner. Using improper refrigerants or lubricants will cause severe damage to your air conditioner system. See "Air conditioner system refrigerant and oil recommendations" in the "Technical and consumer information" section of this manual. A NISSAN dealer is able to service your "environmentally friendly" air conditioning system. WARNING The air conditioner system contains refrigerant under high pressure. To avoid personal injury, any air conditioner service should be done only by an experienced technician with proper equipment. WHA1121 4-22 Display screen, heater, air conditioner, audio and phone systems