The automatic validation tool is a software designed to improve the validation process for HVAC devices through the use of the most innovative systems and concepts, existing nowadays. Due to the steady increase of functions and signals that vehicles suffer, because of automotive technologies evolution. To complement existing validation systems, it arises the need to develop a new software able to efficiently exploit, the large amount of data that is currently obtained at performed validation test. To raise this objective, the developed software consists in: control logic, based in C code programing by CANoe (software provided by the company), and a visual user panel, also developed with CANoe. The system allows automatically evaluating and checking clima signals. As an automated software, it's possible evaluate various simultaneous functions and it's not necessary that the person who drive has knowledge of the clima operations or software functions. In addition, to control the visual interface results, we generated Word and Excel files allowing more optimal management of the results. In real conditions, we have reached a significant decrease on error detection time in vehicles at prototyping stage. Also, we increase the spectrum of verified tests and validate, in a fully automatic way, the Start/Stop system and the feedback air tramp.