3 days after I just installed my newly refurbished Quad race box I got a P0191 code upon start up.

No the quad box is not the problem!!! I unplugged and replugged it just to make sure!

Truck runs fine and extra fine with the Quad race box on!

Check engine light is still on with that dern code.

I called the dealers head diesel mechanic to see if it was a major problem and he informed that, "It was a Cummings deal"

I decided right then and there that I would be much better off taking it up with you guys, than listening to some moron who does not even know what the name of the company is!

Any ideas as to what the problem could be? And or cure?


Rick

 

Oh c'mon guys I'm counting on your expertise here!!

p0191 rail pressure does not match expected pressure....... bad sensor??

Rick

 

It takes a few restarts to get the MIL light to turn off and the code to clear.
Did you smear some dielectric grease on the connectors before installing?

MikeyB

 

Dielectric grease as instructed

As I mentioned the truck threw the code 3 full days after installation upon start up, without the box turned on, that is what has me wondering

Rick

 

So Rick , did you get on it after you installed the box ? you may have popped the rail press valve and is leaking now and making the CP3 scramble to keep up with the command from the ECM .

 

No leaks detected, and no other codes such as high/low rail pressure thrown.

I guess I'll have to remove the box an take it to the dealer since I don't know anyone local with a Bully Dog downloader or a Superchips downloader to clear the code and properly check the system.

And it threw the code at start up! Not while using the box, or just after using the box?

Rick

 

I had the same code some time back.
Took it to the ******* and they replaced the sensor.
Four months later, had the same code show up. They say that DC is aware of the prob but dont have a fix.******* said if it shows up again to bring it in and they will check it and reset.
Kinda sounds like a PIA to me.

 

I just read coupla post back about the 191 and he said there was a TSB coming out for that problem.



check engine lite

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mine came on and i took it to the dealer. had a code of P0191 come up. they downloaded something to the PCM and told me that there would be software coming out in june with a TSB for a reflash for the PCM.

anyway the light has not come back on and the truck runs like a top.

david
socal

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610 ft lb TQ CTD WITH SHORT BOX
3.73 AUTO
SILVER TO MATCH MY 19' TIN CAN (airstream)
.40 S&W
GOD BLESS THE EAGLE, GLOBE AND ANCHOR!

 

Hey Rick , I have a BDDL if you need it... . send me a PM

 

Thanks John,

I'll give you a yell tonight!

Rick

 

Hi guys I had a the p0191 fuel rail sensor circuit performance code and I replaced the sensor it was good for 3 days and getting off the highway at a stop sign it came back again I dont mind bringing it to a dealer but from reading some of these posts they are not sure how to fix it either smh did they come out with a fix or reflash yet???