PACCAR PX-9 CM2350 (2013-17) Fault Code:2311 PID:SID 18 SPN:633 FMI:11 Electronic Fuel Injection Control Valve Circuit – Condition Exists

Reason:
Electronic Fuel Injection Control Valve Circuit – Condition Exists. The fuel pump actuator circuit resistance is too high or too low, or an intermittent connection has been detected.

Effect:
Possible reduced engine performance.

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

Component Location:
The high-pressure fuel pump is mounted to the gear housing. The fuel pump actuator is mounted on the fuel pump. The fuel pressure sensor is mounted in the high pressure fuel rail. The fuel pressure relief valve is mounted on the high pressure fuel rail.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes:
The fuel pump actuator circuit had an intermittent circuit concern, or the fuel pump actuator resistance was too high or too low.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) Sensed fuel rail pressure will not follow the commanded rail pressure.
3) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
4) 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 Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5) 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 Talk:
If 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:
1) Fuel pump actuator high resistance
2) Engine harness high resistance
3) Loose, worn, or corroded connectors or pins at the fuel pump actuator or ECM connectors
4) Fuel pump actuator with low internal resistance
5) Fuel pump actuator or engine harness that has shorted to ground
6) Intermittent 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 Causes:
1) Inactive fault codes
2) Faulty fuel pump actuator
3) Short to ground
4) Faulty engine harness resistance
5) Faulty ECM