tomm

Got this this morning, check engine light is on all the time.
Other posts from around 2004 say it's a "fuel rail pressure" issue and may be caused by turning the key to on and waiting too long to turn over engine.
2004 is awhile ago, anyone get these lately?

thanks

Nomo stocker

Yeah, my truck just threw the same code. Hope someone knows something.

CD in NM

I have had this code several times. Each time, off to the dealer, each time they do a flash and clear it. It IS possible that having the key on for too long could cause the code as the fuel management system must have a timeframe that it expects you to start your truck or expects it to be running in a certain amount of time, so the code. I would say that it depends on if you got the code while waiting for the grid heater to start the engine also. Now that we are into colder weather, waiting for the grid ehater, more and more people are getting the code.

I finally had enough of all the trips to the dealer and just got the kit to cap the rail. I have not had the problem since. So I believe that it is the relief valve causing the problem. It is cold overnight where I live, I am waiting on the grid heater, and no code. I even had the key on for an extended amount of time the other day, no code. Previously when I got the code I did not have the key on too long or was not waiting too long to start the truck - personally I think that excuse is a lame one. I can tell you that EVERY time I threw the code I had been running in a 45 mph zone, in 4th gear crusing the zone, and immediately following that zone is a steep downhill grade that I use the gear to hold back the truck and of course at that point I am NOT using the throttle/fuel feed so the rail pressure WOULD see a major decrease in demand but the truck is still running so there IS rail pressure. It kind of told me that the relief valve would be defueling due to the demand just prior to the hill and the lack of demand in the hill, so it acts like an over pressure momentarily.

I hope that helps with some idea of a trigger for you guys, if you were driving similarly to my experience, you probably have the code for the same reason. I made a ton of trips to the dealer have this code cleared. It became obvious to me that they are re-setting the interval the computer sees regarding LOW fuel/no fuel demand times in the fuel management. I would imagine that every time it is re-set the interval time is extended more and more. They did change my relief valve once, but did not indicate it on my paperwork. Must have been testing one they took out of another truck with the same problem, nothing like being a parts tester rather than solving the real problem?

I finally told them I had enough of the regular visits and was going to cap the rail and remove the relief valve. I also told them that they had better not give me warranty crap as they were not living up to their warranty in solving the issue. I told them that when a TSB or recall finally took place regarding either the valve or whatever was responsible I would be back for the warranty repair I was entitled to, till then RAIL CAP. I drive sensibly, I do not have added power boxes, and I cannot see the CP3 produdcing fuel pressure that overpowers the rail capacity. We all know that there is some kind of engineering issues to the fuel system in one part or another, this is just one part of many. You can have quality time with a lot of things in a lot of places but a truck dealership is not one of them unless you are looking to buy.

welndmn

Where's you get the kit?

CD in NM

welndmn - sending you a pm.

CD

HOV

Can you post it up so we all can see?

CD in NM

I am not familiar with the site rules regarding posting info from someone that may/or may not be a paid advertiser. So, if my next post finds itself in the trash, so be it, you will have to pm me or I will pm you upon request.

CD

CD in NM

I got my Rail Kit from NGM Diesel Performance. 301-884-2175.

I know that many guys just cap the rail, and they do it with the right sized bolt, and call it done. I wanted something to deal with the fuel lines and return of the fuel somewhere, this kit gets the job done very nicely. I also know that i could have taken the time to put the parts together myself and saved a buck or two, but it was just easier to get the kit. I had been carrying the kit in my toolbox in case the relief valve stuck open and left me without rail pressure and no go power along side the road in the middle of nowhere, but I really got tired visiting the dealership all the time.

I hope this helps whoever needs this kit out of their problems.

CD

79warlock

Have you had the TSB performed? The dtc is only supposed to be set if rail pressure is above 870psi with key on and not running/cranking. Basically it lets the ECM make sure the rail pressure sensor is still in calibration. The sensor should be reading very close to zero. If it is always active, you either have an issue with the wiring to or the rail pressure sensor itself.

CD in NM

79warlock.

If you are asking me if I have had the TSB done for the 0191 code, my answer is yes. Actually, they have done it a couple of times, or whatever they do when you take it in to have them clear the code. I do know that they have commented at least once that my sensor is 'within the limits', but I have gotten the code too many times while traveling down the road under varying circumstances that could create a momentary de-fueling and subsequently cause the P0191 code. The wiring is all good, they checked it, I checked it (wonderful thing those schematics) and they have replaced the sensor once. It is an operational problem or a programming problem or both.

CD

79warlock

That seems strange to me, maybe they should have called the STAR center. That code should not be set while driving, it supposed to set if the fuel pressure is reading high when the ignition is on but engine is off. I had that code on an 06 and in the freeze frame data the vehicle was indead off when it set. In that case, I cleared the code and it never came back.

RamDiesel10

I have the same code p0191 I replaced the frp sensor and it went 3 days and came back on again I have a friend thats a tech at dodge and he said my software is up to date not sure if that means any tsb were done for this issue I may bring it there once and see if they can try a flash and check it out etc...