Connect 12 volts to EGR motor main power terminal, connect earth to EGR main ground. Valve should fully open
Connect 5 volts to sensor signal in, connect sensor ground to earth. With EGR valve fully open sensor signal out terminal should read 4.5 volts.
Connect 5 volts to sensor signal in, connect sensor ground to earth. With EGR valve fully closed sensor signal out terminal should read between 0.5 volt and 1 volt.