PACCAR PX-8 CM2150 (2007-09) Fault Code: 2311 PID: SID 108 SPN: 633 FMI: 11 Electronic Fuel Injection Control Valve Circuit – Condition Exists. Fuel pump actuator circuit resistance too high or too low.

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM.

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

Possible causes:

1)Fuel pump actuator high resistance
2)Engine harness high resistance
3)Loose, worn, or corroded connectors or pins
4)Fuel pump actuator with low internal resistance
5)Fuel pump actuator or engine harness that has shorted to ground
6)Intermittent circuit failures 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 faulty, 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 faulty.

Possible repairs:

1)Replace the fuel pump actuator.
2)Repair or replace the engine harness.