Frequently Asked Question

Overview

The VDO pressure sending unit converts a pressure into a variable resistance output. They can be identified by their one or two terminals on the side opposite the pressure connection. The sensor will be stamped with its pressure range and brand on the flats used to tighten the sensor, at the pressure port end. The sender is wired to the EIS in so that the 4.8V sensor excitation output provides a regulated voltage through a resistor to the sending unit. The variable resistance of the sending unit cause the voltage to vary across its terminals. With no pressure applied, the sensor will have about 10 ohms resistance. With increasing pressure, the resistance increases.