I was wondering if anyone knows how the EGR valve electrical control works, i.e. which sensors the PCM takes input from in order to command the EGR open/closed.

Background:
About a year ago I replaced my EGR valve after some electrical gremlins. But I'm once again getting a P0404 code for the EGR valve circuit. The only other noticeable symptom besides the MIL is that there is a strong fuel odor on cold engine start.

I pulled the EGR valve and did a voltage test on the connector with the key on and engine off, and got two 5V signals and a 12V signal. Does this mean that the EGR valve is being commanded on during a cold startup? And should it be? Or is this a sign that one of the other sensors is feeding bad data to the PCM?

 

The E.G.R. valve has a position sensor in it. The p.c.m controls it according to this input. You should not have any egr flow when cold unless the valve is stuck open. It would then cause a hard start or rough running. You should not really smell gas as it recirculates exhaust. If the gas smell is under the hood look for a leak. If it's a 3.3l check out the electrical connectors at the front of the intake manifold (belt side) for corrosion/green this is a problem area that can affect the position sensor.