just trying to build a test spec up for checking voltages ect of the sensors whilst connected to the ecu... i have the resistances for the ECT and ACT sensors and these are NTC sensors.... so as the temp increases, the resistance decreases.

with the 5v supply from the ecu as supply in to what is effectively a potential diveder circuit Vout=((R2xVSupply)/(R1+R2))

leads me by calculation that teh input resistance on th ecu itself is somewhere around the 2.5K ohm mark. Can someone confirm this either by measement or data book...?

with 2.5K as the R1 valve, 5 as VSupply and the sensor itself as R2, i can get a nice graph in excel of voltage across the pins of the ecu vurses temperature, instead of open circuit resistance