THE CONTROL METHOD OF AIR CONDITIONER FOR VEHICLE

A method for controlling an air conditioner for a vehicle is provided to learn a warm-up pattern and a cool-down pattern of a cooling water temperature under real car conditions, and estimate a current cooling water temperature value accurately in accordance with learned warm-up pattern the cool-down pattern in case that a cooling water temperature sensor is disconnected or removed, thereby controlling cooling water at the optimum state under real car conditions. A method for controlling an air conditioner for a vehicle steps as follows. If a cooling water temperature sensor is abnormal after starting a vehicle, warm-up time is initialized and time from a starting-off point to the current point is calculated to calculate cool-down time(S101-S104). A warm-up table and a cool-down table which are in the middle of storing are loaded(S105). It is checked whether set cool-down time is terminated(S106). If so, a cooling water temperature value set by warm-up time is recognized as an actual cooling water temperature based on an external air temperature coincided with the current external air temperature of a warm-up pattern which is being stored on the loaded warm-up table(S107-S109). It is checked whether warm-up time is terminated(S110). If so, the final cooling water temperature value is maintained(S111).