Circuit DescriptionThe circuit is a pulse-width modulated (PWM) driver in the engine control module (ECM) that controls the electronic fuel pump actuator. The actuator is grounded in the ECM. The actuator is normally open. The PWM duty cycle to the electronic fuel pump actuator depends on the difference between desired rail pressure and sensed rail pressure.

Component LocationThe fuel pump actuator is located on the engine-mounted fuel pump. The engine wiring harness and the ECM are other components in the circuit that can cause this fault code.

Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON position.

Conditions for Setting the Fault CodesThe ECM has detected a short circuit to ground in the fuel pump actuator signal or return circuit.

Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE lamp and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.Sensed fuel rail pressure will not follow commanded rail pressure.Active and stationary regeneration of the diesel particulate filter will be disabled.The 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 using a Diagnostic Road Test, utilize a route that incorporates both stop-and-go city driving and steady state highway driving. It may be necessary to load the unit for certain diagnostics in the ECM to run.To validate the repair using a Chassis Dynamometer Test, utilize a routine that incorporates acceleration and motoring events, steady state highway operation, and load. This will simulate normal driving and allow the diagnostics in the ECM to run.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 engines.

Shop TalkThis fault becomes active when the ECM detects a short circuit in the electronic fuel pump actuator circuit. Causes for this fault code are short circuit to ground or low resistance (fuel pump actuator coil is shorted internally) in the circuit for the fuel pump actuator. When excessive current or a short circuit is detected, the ECM driver to the fuel pump actuator is turned off to protect the circuit. It is necessary to cycle the keyswitch OFF and then back ON before the ECM will test again for the cause of the fault code. The ECM driver is enabled at key ON; if the cause is no longer present, the fault code will become inactive and can be cleared. If the fault code is intermittent, look for causes of an intermittent short to ground in the wiring harness or connectors.

Fault Code 2311 can have high counts if the short circuit condition is or was intermittent.

Possible Cause:1) ECM failure2) Engine Harness