The invention comprises several vehicle parameters transducers (1, 2, 3, 4) associated to respective slave circuits (10, 20, 30, 40) connected by a single, time-shared serial bus (60) with a master slave (50) which, when activated from a digital processing unit (DP), performs a communication with each one of the slave circuits, a bit frame circulating through said serial bus (60) according to a transmission protocol, without error correction, formed by a series of bit packets, each one with information from a corresponding slave circuit and separated by a short time interval, which information is stored in said master circuit (50) from where it is acquired by the (DP) through a parallel bus (70).