dieselfreak21

So I did this by pass and gutted the filter. Turbo now clean and staying that way. Truck smells like a diesel a little. All is good for about 300 miles. Then CEL . P04DB-CCV disconnected. So I remember i did have to unplug something to get to the filter, maybe I forgot something. Nope I had plugged the sensor back in. Go have the code cleared. Goes 30 miles, get the same code. Oh and the smart @$$ engineers decide that when the CEL light is on your auto start no longer will work. Do more reading, find this senor is on UREA and newer trucks. Non Urea trucks don't have the sensor from what I can find. So I pull sensor and get to testing to see if I can fool this thing. It is fed with 5 VDC. I apply pressure no change in resistance. I try vacuum. My source is human powered as I didn't want to break a $50 senor. There is very little pressure coming out of the tube and from other forums there is little to no vacuum at the factory inlet on the turbo intake tube. Truck was still a little warm when pulled the senor and my hot air wasn't helping it cool. So i took a lunch break leaving the senor on the work bench. I noticed the resistance has dropped alot now that it has cooled. So I apply warm air to it and finally get a resistance change. Very slight. So I decide to plug it. Drove it over 330 miles with numerous on off cycles thinking it would turn it off. Of course not. Now have code I've always had and got a new one P04E4. Something about the senor reading is erratic. Guess when i plugged it that caused the issue.
So now I have truck that auto start won't work ( i know first world problem) and more questions than answers.

Does anyone know what the recommended repair sequence is for this new code?

Does anyone know the exact specs of that senor so I can attempt a sim?

Is it possible they are looking for heat as opposed to any pressure/vacuum since there really isn't any?

Does anyone know the voltage range the ECM is looking for, for normal operation?

I see cummins has improved CCVF for their Over the Road Engines that appears to have built in oil separator. It has a sensor, anyone know if it is compatible?

Hey FIAT, Cummins Engineers stop reading our forums and coming up with these sensors to read when we make our trucks better since you had no better design for CCV closed loop.

BigIron70

Here is diagnostics for what it's worth

dieselfreak21

Thanks for the info BigIron70. I see they tell you what trips again when the think the senor fails but they hold on tight to the voltage it is looking for. Any chance you know where I could find that? I ran it with the senor plugged but installed. I guess it is looking for some type of pressure/vacuum and not just heat as i suspected.