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Programmers or Tuners Can Cause Codes be To Set

Duramax Fuel Pressure Regulator Code Diagnostic P0090, P0088, P0084, P0087

High pressure fuel is regulated by the fuel rail pressure FRP regulator mounted on the fuel injection pump. The FRP regulator is controlled by the engine control module ECM, The FRP regulator has a solenoid supply voltage circuit and solenoid circuit. The ECM monitors the current on the circuits to detect a failure.

  • There are no driveability concerns associated with the FRP regulator unless a DTC is present. The most likely cause of this DTC is a sticking FRP regulator
  • If the fuel system pressure is actually too high, a fuel knock condition will exist.
  • If the fuse that supplies voltage to terminal if the ECM is open, this DTC will set  
  • If P0087 is a present code you will need to check this areas of you truck
  • 1. A restricted, kinked, or damaged fuel supply line may cause DTC P0087 to set
  • 2. If low fuel condition is present and DTC P0084 sets, inspect the fuel sender pickup tube for damage or perforations.
  • 3. Water or gasoline contamination may cause this DTC to intermittently set
  • 4. When ambient temperatures are below 0%, the fuel tank pickup screen may be iced over from water in the fuel tank
  • 5. If the fuel pressure relief valve is not torqued correctly, the valve will leak fuel into the fuel return system causing this DTC to set. The fuel pressure relief valve uses a bite type seal, an proper toque is essential for the valve to rail sealing.
  • 6. High fuel injector return flow may cause this DTC to set.
  • 7. The addition of the fuel system enhancements, such as auxiliary fuel tanks or add on products such Programmers or Tuners can cause this condition or relate to driveability complaints P0088
  • 8. Turn On the ignition and observe that the desired FRP regulator parameter and FRP regulator command at the same mA values . 
  • 9. The fuel pressure difference between the fuel rail pressure and the desired fuel pressure should be thss then 5 MPa different 
  • 10. Dont let you get this condition frustrate you call a local shop or Toxic Diesel Performance for help 

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