The invention is a system for transmitting signals in a vehicle, comprising a sensor that generates sensor signals, an information display device that receives the sensor signals and a transmission conduit through which the sensor signals are transmitted. The transmission conduit comprises transmission line that may be dedicated for purposes other than transmitting the sensor signals, modulator, demodulator and control device. When the sensor is actuated, the control device acts to detect the presence of current in the transmission line and if present, actuates the modulator thus, modulating the sensor signals prior to their transmission via the transmission line. Simultaneously, the control device actuates the demodulator for demodulating the modulated sensor signals prior to their transmission to the information display device. If, however, current is not detected in the transmission line when the sensor is actuated, the sensor signals are transmitted via the transmission line without being modulated or demodulated.