Fuel pressure to high code/ Replaced part code came back

Rhonda Owner Fort Lupton, Colorado Posted   Latest   Edited  
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Driveability
2009 Chevrolet C4500 Kodiak C4C042 6.6L (9 LMM)
P0088 - Fuel Rail/System Pressure - Too High Bank 1

Truck set P0088 fuel pressure to high tested circuit found to be good. Replaced Fuel Pressure Regulator. Truck demands 15000 @idle. Getting 15000, but still setting code P0088. 

No smoke, No knock. No air in fuel line.

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Harm Technician
Fergus, Ontario
Harm Default
 

Very possible that the truck has been tuned? Also i believe that there is a reflash for this code.

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Phillip Diagnostician
Anchorage, Alaska
Phillip Default
 

Is the fuel pressure reading taken via scan tool?

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Rhonda Owner
Fort Lupton, Colorado
Rhonda Default
 

yes.

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Brian Technician
Bridgewater, New Jersey
Brian Default
 

I dont have any specs but 15,000psi seems high for idle.

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Adam Owner/Technician
Edmonton, Alberta
Adam Default
 

Should be about 4500psi at idle

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Phillip Diagnostician
Anchorage, Alaska
Phillip Default
 

That is what I was getting at. I'm not a diesel expert by any means. Also I couldn't pull up that particular vehicle, but a 2009 Silverado with a 6.6 stated "approximately 40 MPa (5,802 psi) with the engine cold, and 30 MPa (4,351 psi) at operating temperature. Based off wiki they both should be a LMM 6.6 engine.

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Albin Diagnostician
Leavenworth, Washington
Albin Default
 

Check the software version. Reflash as needed. The high pressure fuel pressure is controlled by the PCM by using the fuel volume valve in the high pressure fuel pump. Can you change the fuel pressure with your scan tool? 15K PSI at idle is a tad high. Either the software is askew, or something is wrong with the pump control. If perchance you do remove the fuel volume control solenoid, take a…

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