GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 Sierra Denali 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC P009E

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provide an overview of each diagnostic category.

DTC Descriptor

DTC P009E: Fuel Rail Pressure Relief Valve Performance

Circuit/System Description

The engine control module (ECM) uses the fuel rail pressure (FRP) sensor to monitor the high side fuel pressure and the fuel rail pressure relief valve performance. The fuel rail pressure relief valve is designed to release fuel pressure in the event of an overpressure condition. This diagnostic looks for excessive fuel rail pressure decay to detect an open fuel rail pressure relief valve.

Conditions for Running the DTC
    • Engine is running.
    • Fuel rail pressure is more than 189 MPa.
    • This diagnostic runs continuously.

Conditions for Setting the DTC
    • The stored fuel pressure deviation values, during three diagnostic events, are all above the calibrated limits.
        OR
    • The sum of the stored fuel pressure deviation values are above the calibrated limits.
        OR
    • One or two fuel pressure deviation values are above the calibrated limits and the fuel rail pressure valve is stuck in the open position.

Action Taken When the DTC Sets
    • DTC P009E is a Type A DTC.
    • The ECM commands the engine to operate in the Reduced Engine Power mode.
    • A message center displays Reduced Engine Power

Conditions for Clearing the DTC

DTC P009E is a Type A DTC.

Diagnostic Aids
    • Fuel level below 11 percent may cause this DTC to set.
    • A restricted fuel filter, kinked or damaged fuel lines may cause this DTC to set.
    • Inspect for poor fuel pressure regulating if this DTC sets at cold engine idle. Refer to Fuel Pressure Regulator Diagnosis .
    • This DTC may set when hot engine conditions are present. Refer to Fuel System Diagnosis .
    • The valve will leak fuel into the fuel return system causing this DTC to set if the fuel pressure relief valve is not torqued correctly. Refer to Fastener Tightening Specifications .
    • An intermittent electrical connection at the fuel rail pressure sensor may cause this DTC to set.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Testing

If any other DTCs are set other than DTC P009E, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

  1. Remove the fuel pressure relief valve return hose and plug the hose to prevent fuel leakage.
  2. Install a section of rubber fuel hose on the fuel pressure relief valve connection and place loose end of hose into a clean fuel container.

    3.    Important: Fuel that is contaminated with gasoline may cause permanent damage to the fuel pressure relief valve. Refer to Contaminants-in-Fuel Diagnosis .

    • If the engine cranks but does not start, crank the engine for 15 seconds. Observe for no fuel leaking from fuel pressure relief valve.
         ⇒If fuel leaks from the fuel pressure relief valve, replace the pressure relief valve. Refer to Fuel Pressure Relief Valve Replacement .
    • If the engine starts and runs, idle the engine while commanding the fuel rail pressure to 180 MPa with a scan tool. Observe for no fuel leaking from fuel pressure relief valve.
         ⇒ If fuel leaks from the fuel pressure relief valve, replace the pressure relief valve. Refer to Fuel Pressure Relief Valve Replacement .
         ⇒If the fuel pressure relief valve tested normal, refer to Diagnostic Aids.

Repair Instructions

Important: During code clearing, the ECM must be powered down. Power down is achieved by turning off the ignition key and waiting for loss of communication, indicating power down. The time to power down may vary from vehicle to vehicle. After power down is achieved, turn the ignition key to the ON position and clear the trouble code using the scan tool clear code function and power down ECM. Repeat power down if the trouble code does not clear on first attempt.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel Pressure Relief Valve Replacement