I've had this code on my 2000 Jimmy for years. The vehicle has no rough running when the code is set, like I've read an actual faulty EGR will cause rough running. Read alot of posts but never seen a definite conclusion. I did the "clean EGR and install new gasket with screen". Didn't fix it. Have never bought a new EGR valve because I've only read it doesn't fix the problem. Can anybody say for sure, what the chances are of this code actually being fixed with a new EGR valve? Or was it wiring? Something else? I know there are alot of posts about this. But again, no conclusions. People just quit posting without saying what is the fix.?

 

Anytime you get a code for a system with a sensor or actuator, motor, etc you should always check the wiring first. Test all 12v and 5V reference or power levels, the quality of the grounds and the signal wires.

The first thing to check here is the 5V reference voltage at the Gray wire at the EGR valve connector and its lo ref ground on Black wire. I can help guide you if you want to test your wiring and levels.


George

 

I ran across that testing last night but didn't bookmark it. If you'd like to explain the testing I'd appreciate it. Thanks!

 

Lets start with the 5V reference and the reference ground. You should always test power and ground with the load attached or a simulated load drawing the same current because some problems do not reveal themselves with an open circuit (connector removed and load disconnected). The 5V reference level is critical so its not like battery power that can swing a couple of volts and the truck will still run. Also, reference ground or lo ref is a conditioned, isolated ground to keep the 5V reference power and signal levels nice and clean as apposed to using a frame connection. With everything attached and the ignition in run back probe the gray and black wires at the EGR valve with a digital meter in 20VDC mode and report back.

George

 

Your explanation and procedure makes much more sense. The other instructions I read was testing the connector while unplugged. I'll get back with you asap. I have no garage and weather isn't cooperating at the moment. 😁

 

One question. Key in run position only, or truck running?

 

I think key in run only but if you don't get 5V then start the truck and retest.

George

 

I got 5.01v between the gray and black.

 

Ok so your 5V reference is good. Next up is the brown position output signal wire to make sure it has good continuity, no shorts to ground and no shorts to power.

Disconnect the Egr valve at the connector and connector C2 at the VCM for these three tests. The brown wire is on pin 10 on C2.


George

 

I have just a basic multimeter with no continuity tester. But I can use the resistance, correct? Also how am I checking for shorts to ground and power?