i know its suppose to idle up but dont understand why sometimes its starts out at 1000 rpm and sometimes it starts at 750 for a minute or two before it speeds up to 1000 rpm but thanks again every bit of info helps

 

It goes off of the intake air temp, same sensor as what controls your pre heater and how long the light stays on. Couldn't tell ya what temp it makes it start out at 1000 though.

 

update : after running a battery of tests i think we fixed it, all i could find wrong in the intire truck was that the fuel pressure sensor and fuel control actuator were not working properly. so my theory is that when temps fall below freezing the fuel thickens a little so the pressure drops . which in turn shuts down the truck. 3 days now so far so good . i will update in a couple weeks if this isnt the fix

 

wrong again , still dies. runnin out of ideas

 

did you ever fix this problem? im having the same problems with mine

 

One common issue with these trucks was some were produced with connecters at the ECM that would corrode. Remove the connector, check for corrosion, add some dielectric grease if you have some, and re-seat it...see if that solves the issue.

 

Also try unplugging the FCA (2 wire plug on InjPump) then crank. See if it continues to run with it unplugged. It will sound different but see if it dies. Dont drive it like this because it sends your fuel rail pressure to max. If it doesnt do what you described earlier, thats your problem. I had the EXACT same symptom you described and that was what fixed mine.

 

My 04.5 does the same thing depending on how cold it is outside.

 

This happend to my 06 when it was like 45* out.. clean the cables for batteries.. not the wire brush style the actual cutting style it cost like 7 bucks at O'Reilly auto. Clean all the cables and posts on your batts and it should fix the issue. The use the terminal protector.. did the trick for me.. if not is start checking connections going to your Ecm and pcm

 

You need to check and wiggle test the ecm power circuit. That code is rare. Some where in that ECM power circuit there is a break or rubbed through spot. Find the schematic for the circuit and go over it with a fine tooth comb. What about and intermittent short in the ignition switch?