Update: 99 Silhouette engine swap to LX9/3500

[Lumina3.5]

The way you have the wires matched is exactly how mine lined up when I had the dying issue. For the last few days just to test it I've had the following spliced configuration:

EGR Valve Control- Gray = EGR Solenoid Low Control- Gray (spliced together with) EGR Solenoid High Control- Orange
EGR Position Signal- Brown = EGR Position Signal- Brown
5 volt Reference- Gray = 5v Reference- gray

This setup took away 2 of the 3 EGR-related codes in my PCM but P0403 remains...At least it still doesn't die though. I just left the Red 12v and black ground wire disconnected. I figured the 05 solenoid must be set up to ground itself to the intake? Still not really sure but from my untrained electrical guess, the 05 PCM must send varied voltage (dependent on engine speed) to the EGR through its gray and orange control wires? That is, whereas the Silhouette sends 12v hot to the EGR all the time when key is on?

I'm pretty ignorant to how it all works but from what I have read this conclusion kinda makes sense to me...Not sure if there is really a good no cost solution short of retrofitting the 99 EGR and tube back to the 3500 intake. If that's the case, I'm just gonna put a piece of black tape on the cluster over the light! I'm done spending $ on this thing!

[3400-95-Modified]

I don't know what else to say... I run an 05 3400 egr on my 96 with a 97 ECU setup the same way as my 96 was and I have no issues... never had to change any wires.

I will say after looking at pictures of an 05 3500 EGR online it's not the same as the one that came with my 05 3400, and I bought a 04 3500 which by application has the same EGR as the 05 3400's

Maybe that's why I don't have any issues. So to sum it up, an 04 3500 and 05 3400 egr are the same... and any 2000+ 3400 egr will bolt to a 3500 intake plenum.

[Fireball]

I don't know what else to say... I run an 05 egr on my 96 with a 97 ECU setup the same way as my 96 was and I have no issues... never had to change any wires.

I'm curious as I've got a 3500 EGR sitting around at home and I know my 3100 one is bad.
When I put my 3500 manifold back on I'll stick the 3500 EGR on there.

I'll let you guys know what happens (keeping in mind that this could be a few weeks or more).