Another EGR trouble code

2000 Century. A couple of weeks ago I had DTC's read, came up with P0401 EGR Flow Insufficient. By recomendation of a post from this board, I took EGR valve off and checked for plugging. While it was off I cleaned it up some. Replaced EGR valve, had the codes cleared and everything was good. Thanks for the advice.

Yesterday morning I started to drive and SES light came back on. Had codes read today. P0405 EGR Flow, Sensor A Circuit, Low Input. Anyone have any ideas on this code? Please help.

Thanks,

According to my GM Mode 6 listing DTC P0405 is EGR Valve Position Sensor Circuit Low Voltage. The EGR pintle position feedback circuit is either open or shorted to ground.

Did you replace the EGR valve with another? Sounds like the electrical portion not mechanical of the EGR valve is bad.

Did you replace the EGR valve with another? Sounds like the electrical portion not mechanical of the EGR valve is bad.

Have not replaced the EGR valve, was hoping cleaning it would fix the problem. Any idea which terminals on the valve are the coil terminals and which are the pot terminals? I could then check these terminals for continuity or actual resistance. Any idea what the resistance should be? I am guesiing that the voltage from the EGR valve back to the ECM is what is low indicating that the pintle is in a position other than what the ecm is comamnding and thus setting the code?
Thanks,