Sorry for the long post guys but I need a little help. Here's my predicament:

My truck keeps tripping a CEL and throwing code P0191. Like I posted before, it fires up, immediately stumbles and drops RPM to about 500, then jumps back up to a normal 750 RPM idle. When it does this, it will occasionally surge to about 1000 RPM then drop back to a normal 750 RPM idle again. It has done this now about a half dozen times, all within the last 4 weeks, and the last time being mid-morning today (after the truck was already warm).

Yesterday morning when I hopped into the truck to high-tail it to work it wouldn't start at all. It would try but it wouldn't quite get there, sounding like it was starving for fuel. I immediately reached under the dash, unplugged the Quad module replacing it with the bypass plug, and it fired right up. The odd thing that time is a CEL was not set. I immediately thought the problem was with the box, but since it had an episode again today I no longer believe this to be the case.

Here's where Ryan Frahm comes in. I think it's time to take it to a dealer, but I don't have the time or patience to get d!cked around. Ryan's dealership is close enough to me that I can take the truck there, but far enough away that I'd have to make arrangements to do so. But if I know they'll actually look past the Commander and look for a problem I'll happily make those arrangements. So Ryan, do you think the boys at your shop can help me out? Or do I need to go elsewhere, like Ontario Dodge .

Finally, if any of you gurus have any input, fire away. I'm a perfectionist and an **** SOB so even though the truck can be driven my inner OCD is pushing me to resolve this issue.

Thanks all for the help...

 

Are you absolutely sure all your Quad connections are tight and moisture free??
Can you turn the Commander off? Could it possibly be causing any of these problems?

 

As sure as one can be without running a moisture content analysis ...meaning there are no visible signs of moisture . I can't see how the Commander is the problem when it's basically just a monitor without a module to control, and only taps the MAP and coolant temperature sensors.

This is pertinent information: although my sig says I have the fuel pressure option on the Commander, I never installed any part of it (just laziness on my part). So the fuel pressure sensor hasn't been screwed with.

 

If I am not mistaken there was actually a TSB out for the 06 trucks and maybe the 05 trucks as well for this particular code. Most people were getting at startup and it had something to do with the factory programming?

I wished I knew the TSB number.

 

P0191 is Rail Presure Sensor Circuit Range/Performance.

If the the rail sensor plus is on good, clean and tight, check that the plugs on the back of the CP3 are on tight too.

 

Thanks Smkn600CTD, never thought about checking the plug at the CP3. I'll check it out.

 

Glad to be of service

 

mine was doing similar things. I sprayed all connections with contact cleaner and made sure they were good and tight and its been fine ever since. Im guessing i got diesel on the one connection when I did my fuel filter.