Duramax Diesels with DTC P009E - keywords 07 08 6.6 6.6l cal calibration code connector diesel ECM engine fuel injection injector LMM md MIL module PCM pressure pump rail relief SES valve

This PI was superededto update Recommendation to engineering investigation. Please discard PIP4105D.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

A dealer may encounter a customer vehicle with DTC P009E for Fuel Rail Pressure Relief Valve Performance setting intermittently.

Complete the current SI diagnostics for any symptoms or trouble codes set. P009E will set if the ECM interprets a rapid loss of fuel rail pressure. This can occur with a Fuel Pressure Relief Valve leak, a terminal tension/wiring concern at the Fuel Rail Pressure Sensor, or a fuel system suction side concern.

1. If P0191 P0192 or P0193 (fuel rail pressure sensor performance/circuit codes) are set in combination with a P009E, use the current SI diagnostic and diagnose the fuel rail pressure sensor DTCs first. Make necessary repairs to fuel rail pressure sensor and re-evaluate P009E to see if it resets.
2. If the current SI diagnostics for P009E are inconclusive, there has been a updated calibration released to address intermittent P009E. The new calibration can be found in TIS2000 with the title, "P0402, P041D Robustness Improvement, Allow Exhaust Filter Service Regen w/ P244B set, Turn off P009E & P2459, EGR Max Service Device Control increased to 10 minutes."

Note: When completing the diagnostics for P009E a technician may notice the Fuel Pressure Relief Valve has opened and fuel is returning to the fuel tank. If a relief valve is returning fuel to the tank, and continues even after is has been replaced, it is possible to have a sticking Fuel Pressure Regulator. If the regulator was to stick in the open position it may cause repeated high fuel pressure, and induce the relief valve to open. Replacement of the Fuel Pressure Regulator may be necessary if the relief valve repeatedly opens even after it has been replaced.

Notice: Aftermarket modifications such as performance enhancing power up kits increase rail pressure and could also induce a P009E.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.