EGR testing 99 Savana 2500 350

[Frugal Mogal]

Hello, I am a bit stumped pls.

 

I'm having a bit of trouble testing my egr valve operation on this motor. I've been attempting to address a drivablity issue and no trouble codes for help. I believe I understand how the EGR valve is controled by the PCM, and by all accounts (schematics, tech sheets, forums, videos) I seem to be right. 5 pin connector, Middle 3 connections are 5v ref, pintle position potentiometer, and ground (not part of my dilemma)... outer two pins are 12v constant feed from PCM (next to 5V ref) and PCM control provided by PWM ground, which are my dilemma. @ KOEO I have no 12v feed at the EGR harness connector . Both feed and control wires have been tested for continuity to ground and continuity to their respective PCM harness pins (C4 16 & 20). I wanna call the PCM, but, of course, I like to be sure. So, when I go look on my other two same era vans with the same motor, I find the same results. So now I'm questioning myself. Either all 3 motors have failed the same way or my brain has failed.

 

GM Troubleshooting flowchart step advises to command the EGR to 30%. my scantool is nice but not that nice, lol.I can manaully energize the solenoid and eyeball the pintle movement. I can also manually move the pintle with my torx tip and see the movement on my scantool (EGR actual % and EGR V)

 

I measured @ KOEO across Battery & EGR harness connector (disconnected):

B+12V - PCM control circuit = 3mv
B+12V - pintle circuit ground = 12V
PCM 12V feed - B- = 40 mv
5V pintle ref - B- = 5V

 

thanx much!