2005 Chrysler Town & Country 3.8 P0406 EGR sensor high- follow up

So herein is a follow up to this following issue with this vehicle:

I proceeded to test the computer driver and the control circuit integrity.

The control wire is dark blue/violet

ground = black/dark blue

But before this test, i tested the egr with test light connected to 12v touching on the control wire and i could faintly here something click.

I proceeded to use a jumper wire instead and I head an audible clicking from the egr to the throttle body of the vehicle. I don't know why that
was. So I think that tells me that my egr is working right?

Next, when I proceeded to test the integrity of the driver and control, unplugged, test light to ground, the test light did not light. I turned the
car on, and proceeded to rev it to see if I could duplicate the conditions, and negative. nothing. no light lighting.

What have I done wrong? Because I did the test just like the book suggested with no results. What's burned? The driver or control?

thanks fellows techs.

Ok thanks I will try that.

So my clicking test on my egr indicates what after by passing it means what?
That my egr valve is good?

Yes sir

Also, after performing the bypass test and hearing the clicking on the egr valve, does that confirm that my egr is good?

Well, before I proceed to these other steps, I’m going to do what you told me yesterday. Which was checking the control wire plugged and unplugged. And see what my test light is showing me.

Herein is the diagram I’m working with:

Sorry for the repetition.

The circuit that I'm working on is power side switched.
I just did the test you suggested, and indeed the pcm is showing control.
unplugged, test light to B+ = test light lights. I heard clicking sounds.

unplugged, test light to ground = test light NOT on.

Sorry Monde, I don't have bi-directional control scanner. just test light and multimeter.

Check this out Monde, this is funny. I checked the control wire key on engine running and i'm getting 12v, connector plugged.
When I unplugged the connector to the egr, I get 0V's. KOER. i'm getting a little lost here. Loosing my way sort of speak.

Ok, so my voltage on the control wire, unplugged, to the egr solenoid is 3.56V
my ground readings are good, way under 100mv.

The only test that I'm not passing is the testing of the driver and control circuit.
After unplugging, test light to ground, the driver is not turning on my test light and there's no 12 volts either. I can't get pass this point.

I connected my light to ground and T-pinned the control wire, dark blue/violet, and
the light should have lit, indicating driver control and control circuit integrity. I have neither. I've hit a brick wall. don't know what to do next. taking a mental break. thanks Monde.

Yes sir, I performed the test you told me to do. Unplugged, test light to ground, koeo, touching the control wire, no light on.

So what’s next? Do I condemn the egr or pcm?
Is my wiring good then?

Thank you watched them both. I’m going to double check myself again by performing the same test of the driver. What I may do different though is that I’m going to t-pin my control and run a jumper wire to my test light connected to ground and test drive the car where I can see the test light or not. What do you think about that? By the way am I plugged or unplugged for this test?
I believe I’m unplugged for this test. Please confirm. Thanks.

Ok, I performed the test again, here it is:
egr connector unplugged
test light to ground
key on engine off
= test light does not light.

Test light to B+ = Test light comes ON.
same conditions as above.
by the way, I performed this test with a 0.01ma computer test light.

Now, tell me what these two tests indicate to me. What's the thought process here?

What is that telling me?

As far as the running conditions that need to be present, my wife just returned from doing errands and the vehicle is hot and assuming in closed loop operation.

Hear this other issue. When I'm performing the solenoid fuctional test on this egr, I hear clicking sound near the throttle body next to my TPS. Is that weird or what? What do you make of that one?

Not trying to butt in here, but are we sure we wanna be chasing a solenoid control issue? :huh: I had a look at the Snappy Troubleshooter for this code, and this is what it had to say:



Above 4.89V for three seconds represents an open potentiometer ground, an open signal wire, or an open potentiometer. Since you've already figured out how to run a bypass test on the solenoid, I'd be curious to know if you can make the code happen by cycling the solenoid wide open while watching the potentiometer signal voltage.