P0148 High Pressure Common Rail

[JCockerill]

My 06 just thew this code for the first time today, has 54K on it, mods listed in sig. I did some searching but seems this code is caused by low fuel supply. then why does the code say high pressure common rail? The fuel filter isn't that old. and i have a fass 150gph pump waiting for install. what are the possible culprits on this code? the truck is fine untill about half throttle, after that when you load it good, it looses power, blows smoke, and then the engine light comes on. otherwise if you baby it, the code won't come back and it runs ok.



thanks for the help

 

[seafish]

IIRC, the first thing you need to do is to remove your Banks 6 gun and then see if it still happens while running the truck stock.
That'll let you know if it is the mod causing the problem, or something on the truck.

 

[TCDiesel]

What pressure is the fass to CP3,Unplug the FCA and see if the truck ramps and rattles.

 

[JCockerill]

do i have to remove the banks competely from truck or can i just disconect it?



twest, i didn't install fass yet i have it in garage on the do do list. what does disconecting fca do? can banks system cause this?



how can i test fca, and rail relief valve?



i will be droping tank to install fass pickup so that should reveal any problems in tank.

 

[seafish]

do i have to remove the banks competely from truck or can i just disconect it?

I hope that someone else chimes in here, but there should be no reason to physically remove the tuner from the truck, as long as you can disconnect it in a way that the truck is running ONLY on the stock ecm without ANY input from the Banks tuner. It might be best to call Banks and ask them how best to do that. Then run the truck under same conditions as before and see what happens.

 

[JCockerill]

I have asked banks before, if i pull the fuse to banks it supose to eliminate it from ecm since it is "downstream" from ecm. i will try this first. what is next after that?

 

[TCDiesel]

JCockerill Call Me 763-228-7121

 

[JCockerill]

i disconected the fca, engine got rough and loud, didn't stall. what next?

 

[TCDiesel]

LV good. . Dissconnect the APPS with truck running. . After re-connecting it will will take some time & driving to relearn. . We are just seeing if this makes some type of engine change. report back VIA phone.

 

[JCockerill]

driving the truck some more with this problem feels more like a lift pump restriction. when you hit the truck off idle it makes good power and then slowly drops off like it is starving for fuel, allmost like it is sucking the fuel canister dry and lift pump can't keep up. or there is a restricted fuel filter. I am going to look at all fuel supply components before i start getting into all of this electrical stuff. make sure all my basics are covered first.

 

[AH64ID]

I don't see a fuel supply issue causing high rail pressure, as thats from excess fuel. So either the FCA is being commanded to allow more fuel than it needs from the Banks (which is a pressure box, among other things) or the FCA is failing and allowing more fuel thru than it should.

 

[JCockerill]

i will eliminate banks from equation, is there a way to test fca? i disconected while running and engine got rough. are these common to go bad on these trucks?

 

[AH64ID]

Its not common, but its also not rare. I am not sure of a way to test, but TWest knows and IIRC he has spare's he "rents" for diagnosis.

 

[TCDiesel]

The PowerPDA is showing good it closely monitors Rail Pressure. . His FCA maybe causing this,generally dis-connecting the pressure sensor will cause the truck to stall, if it keeps running the FCA generally may be bad. CR dose NOT support Logic... ...

 

[AH64ID]

If the PDA is showing good rail pressure and its throwing a high rail psi code?

 

[JCockerill]

there is no display on pda for rail pressure, what am i looking for when disconecting apps? is there any way to test the fca?

 

[AH64ID]

The 2006 doesn't have an APPS in the traditional sense, I am not even sure it has one at all. It was my understanding the TPS was in the throttle, and the APPS was no longer used after 2005.

 

[CKelley1]

it is a good idea to install a taped banjo bolt on the cp3 and add a gauge. the cp3 will work from minus 5 psi to plus 20 psi. i do not think it is fuel remove the banjo bolt from the top of the rail pop off valve and place a buisness card between the banjo fitting and the pop off valve. next start the truck and see if fuel comes out of the popoff valve. if none hit the pedal fast all of the way to the floor when the rpm hits about 2700 rpm slid the foot off of the accelerator pedal and see if any fuel comes out of the popoff if it does the popoff is weak or bad. a new fac and cascade overflow valve from genosgarage.com is not very expensive and while you are there get you a rail pressure gauge. they all use the truck's sensor so go with the cheapest i think it is auto meter. if twest and this does not get it you will have to do a leak down test. the popoff valve is the most common and that is why we did it first. to poor boy the other test you need to do them out in the field where you do not get cought. there is going to be about a gallon of diesel on the ground. the propper fittings for the test is only about $100if you could wait.

 

[JCockerill]

today i unpluged fuse to banks and disconected it's obd II conection to disable it. Truck ran normal again, hesitation was gone and no longer threw code under load. I then hook up truck to mac scan tool, ran threw it's fuel system tests, and check datastream for irregularities. all seemed in check. truck still running fine. . so then i re-connected banks tuner to see if it would go back to problem. Nothing, ran fine. what gives? loose conection or something? I'm glad it's back, just hoping it doesn't happen again.

 

[AH64ID]

Very possibly a loose connection. If it comes back I would disconnect for a few days and see what happens.

Hopefully all is well.