I recently purchased a 06 equinox, everything seemed OK until I took it to get legal and failed emissions for the egr valve. I have no engine light on but do have a code, guess the light isn't working.. I replaced the egr valve and am still having an issue. The egr valve had the horizontal connector and I replaced it with the same. The part I put on was
AcDelco 12633889

Within half a mile I get code p0404 exhaust gas recirculation control circuit range/performance

Any help would be greatly appreciated, I saw the post of having to get the ecu reprogrammed but that only seemed to apply to switching from vertical to horizontal connector. The wiring harness is Delphi so I don't believe that conversion was required on this vehicle

 

 

PO404 Chevrolet Possible causes for malfunction:

1. EGR volume control valve stuck open or closed

2.Faulty EGR volume control solenoid valve

3. EGR volume control solenoid valve harness is open or shorted

4. EGR volume control solenoid valve circuit poor electrical connection

5. EGR temperature sensor and circuit malfunction

You will need to do further work on your EGR system to find and repair the cause of your issue.

You need to check all your wiring harnesses and run a full diagnostic on your vehicle.

 

The Check Engine light isn't coming on because that is a pending code. You can clearly see the status of the light in your picture says "OFF."

The TSB (linked here) states that the Siemens EGR retrofit kit is required for models built before January 25, 2006. If the TSB is applicable to your vehicle (check build date on sticker on driver's door), it's possible that the previous owner installed the retrofit kit, but didn't get the ECM recalibrated.

 

Yes I realize in that screenshot the code hasn't posted yet, I had just reset the codes 2 miles prior. Within 20 miles the code actually post but no light. I checked the build date and it was 9/05 so it does appear someone did the retro fit.
I did some checks on the voltage going into the harness. On pin D (5 volt ref) I am getting the appropriate 5 volts. But on pin C (egr pintle position) I am getting 4.3 volts instead of the .6. I did this test with the key in the on position engine off,and at idle after getting up to operating temps

Would not receiving the recalibration cause this?

 

Finally got it all straightened out. Thanks to ruley73 posting the TSB I went and peeled all the tape off and took a closer look at the wiring. The harness and all had been replaced. But, whoever wired in the new harness had everything completly backwards. Guess they didn't realize the harness goes from E to A not A to E. Thanks for the reply guys