I got diagnostic tree diagram for a EGR trouble code. One of the steps is to check for resistance in EGR position sensor. does anyone know how to test this?

Another step is that I need to check if there is 4.5-5.5V at C terminal of the EGR Position sensor connector? where is this located at?

I also need to measure a 1F terminal voltage of the emission control unit. Where would this be?

Appreciate any comments.

 

The EGR position sensor is the black plastic piece on top of the EGR valve. You can use an ohm meter to check the resistance between 2 of the terminals with it disconnected and opening and closing the EGR valve. Use a volt meter to check for voltage on one of the terminals, but bad EGR position sensors on those are common as dirt so i would just make sure the EGR valve is not getting vacuum at idle then replace it as it's a safe bet the position sensor is bad.