A method is provided for controlling an injection molding system, which includes a mold having an inner surface defining at least two groups of cavities, each group of cavities defining precisely one cavity with one pressure sensor at the inner surface. Each group of cavities is at least partially surrounded by a tempering unit that provides an energy flow to the surrounded cavities. According to the method, a pressure is determined in each group of cavities of the at least two groups of cavities. A reference pressure is determined for each group of cavities. A difference between the reference pressure and the pressure in at least one group of cavities is determined and controlled to become minimum by manipulating the energy flow of the tempering unit.