Circuit DescriptionThe circuit is a pulse width modulated driver in the engine control module (ECM) that controls the fuel pump actuator. The actuator is grounded in the ECM. The ECM varies the current to this valve to provide the correct fuel flow to the high-pressure pump based on engine operating conditions. The fuel pump actuator valve is a normally open valve. High circuit resistance can cause fuel pressure to be higher than commanded at light loads.

Component LocationThe fuel pump actuator valve is located on the engine-mounted fuel pump housing.

Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault CodesThis fault is set when the fuel pump actuator circuit has intermittent circuit problems, or the fuel pump actuator resistance it too high or too low.

Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE light and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.Sensed fuel rail pressure will not follow the commanded rail pressure.Active and stationary regeneration of the diesel particulate filter will be disabled.The exhaust gas recirculation (EGR) valve will be closed.Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.Conditions for Clearing the Fault CodeTo validate the repair, start the engine and let it idle for 1 minute.The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.For On-Board Diagnostic (OBD) engines, the ECM will turn off the MIL after three consecutive trips where the diagnostic runs and passes.The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop TalkIf this fault code occurs during a road test, verify that all connectors are clean and free of corrosion before replacing components.

This fault code can become active for any of the following reasons:

Fuel pump actuator high resistanceEngine harness high resistanceLoose, worn, or corroded connectors or pins at the fuel pump actuator or ECM connectorsFuel pump actuator with low internal resistanceFuel pump actuator or engine harness that has shorted to groundIntermittent circuit malfunctions that cause the fuel pressure to exceed the fuel rail pressure relief valve opening pressure.If an intermittent electrical circuit problem of the fuel pump actuator circuit exists, it is possible for the fault code to become active then inactive during normal engine operation. For example, if a poor connection causes an intermittent open or short circuit, the normally open valve will open in a fraction of a second while the circuit is malfunctioning, causing the fuel rail pressure relief valve to open. Following the event that caused the fuel rail pressure relief valve to open, the ECM will attempt to reset the fuel rail pressure relief valve, provided the fuel pump actuator circuit is not still malfunctioning.

Possible Cause:1) Fuel pump Actuator failure2) Engine Harness3) ECM calibration