A P0192 Fuel Rail Pressure Sensor Low to be exact. Does anyone know what this means exactly? The truck has been sitting for a couple days, and I just started her up to park it better in the driveway while I gave her a bath. I look down and noticed the check engine light was on, no fueling mods on the truck presently, only airflow enhancements. I hope it's nothing too crazy as I will be going back to work in a couple days...

 

It means that the rail pressure is too low for what the ECM is setting the FCA duty cycle OR the rail pressure sensor is not working properly.

Low rail pressure could be caused by a leaking rail overpressure relief valve, leaking injectors, a worn CP3 or a bad lift pump.

To troubleshoot, you'll need to crack a few of the return lines (over pressure sensor, head return) and see what is coming back. They should also check the lift pump flow.

Does it happen all the time or only at idle ? How does the truck start ? How does it idle ? Smoke ? knocking ?

 

It just happend at idle while moving around the driveway, seems to idle fine, no knocks, or smoke. It's around 45 degrees out and with semi cold fuel, the LP is reading around 6.5 psi. It seems after the fuel warms up it will read around 8 psi. I am going to head out and get some food now and i'll see how she runs or if the code clears... Thanks for the input!

BTW, when you say "they", do you mean the dealer? Becuase i'd rather not crack the lines on the rail, that spooks me a little, plus I am by no means a CR guru...

 

"It just happend at idle while moving around the driveway, seems to idle fine, no knocks, or smoke. It's around 45 degrees out and with semi cold fuel, the LP is reading around 6.5 psi."

Before or after the fuel filter ? Any chance the filter is blocked and the CP3 is starving ?

"It seems after the fuel warms up it will read around 8 psi. I am going to head out and get some food now and i'll see how she runs or if the code clears... Thanks for the input!"

No problem.

"BTW, when you say "they", do you mean the dealer?"

Someone.

"Becuase i'd rather not crack the lines on the rail, that spooks me a little, plus I am by no means a CR guru... "

The return line coming off the back of the head and the line coming off the top of the rail overpressure relief valve are both low pressure, ie 10 PSI. Nothing to worry about safety wise.

 

"BTW, when you say "they", do you mean the dealer?"

I forgot you had a box on it. Funny you put a box on it and now you don't want to play with the fuel rail.

 

I am reading the fuel pressure right at the CP3 with a tapped banjo. While out and about she seemed to run fine, same as always, although the code did not clear and now I have another, P0633 SKIM Key Not Programmed in PCM, which was weird as it didn't show up earlier.

Awhile back I bought an extra fuel rail, and LP of eBay. I figured they may come in handy one of these days. I didn't want to go with the in tank set up so like the 2nd gen I carry a spare. I've also had the relief valve replaced in the past so I figured this would get put to use eventually as it might now.

"Funny you put a box on it and now you don't want to play with the fuel rail." I'm not sure I follow...

 

"although the code did not clear and now I have another, P0633 SKIM Key Not Programmed in PCM, which was weird as it didn't show up earlier."

your ECM is going south ! Get the box off that truck.

"Awhile back I bought an extra fuel rail, and LP of eBay. I figured they may come in handy one of these days. I didn't want to go with the in tank set up so like the 2nd gen I carry a spare. I've also had the relief valve replaced in the past so I figured this would get put to use eventually as it might now."

??? People need to realize that the stock lift pumps have issues. Not saying that is the problem in this case. If you replace them, replace them with something else.

"Funny you put a box on it and now you don't want to play with the fuel rail." I'm not sure I follow...

"you play, you pay". Once you start moding, your are your own warranty depot. I always thought that people who moded were comfortable working on their trucks.

Your ECM is starting to fail. Apparently it lost your VIN. It was written into ECM flash memory. The VIN is used to calculate the SKIM key.

I wonder if this is related to the other ECM issue currently in the forum, the Bullydog... $1700... post.

 

I haven't had a box on it for a little while now, like I said earlier just airflow enhancements for the moment. I understand I am my own warranty station, this is why I kind of stock up on parts when I see them. I am comfortable working on some stuff, but when it comes to flow rates and crap I know nothing about I rather leave it up to a tech. Also I understand the OEM LP's are crap, but till get around to installing something better they should do me for now. I simply bought the second just to keep me off the side of the road somewhere.

The truck has had in order, but not at the same time... A Ramifier, then an EZ, BDDL, and the latest was an XZT. I did just order the Juice off eBay a couple days ago as a Christmas gift to myself. The BDDL hasn't been on there for quite awhile, do you think this may have been the prime culprit?

 

I dunno, but something is seriously wrong with the ECM. Check the wires talked about in the short circuit wiring post.