PACCAR PX-8 CM2150 (2007-09) Fault Code: 2266 PID: SID 126 SPN: 1075 FMI: 4 Electric Lift Pump for Engine Fuel Supply Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the fuel lift pump circuit.

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.

This fault code becomes active whenever the ECM detects a short circuit to ground or high current in the electric lift pump circuit. Causes for this fault code are a short circuit to ground or low resistance (lift pump partially shorted). During cold weather, gelled fuel can plug the lift pump and cause this fault code. Listen to the lift pump to be sure it is running during cold ambient temperatures (less than -29°C [-20°F]). This fault code can possibly also become active if the lift pump rotor stalls or seizes. When the fault condition is detected, the ECM driver to the lift pump is turned off to protect the circuit. It is necessary to cycle the keyswitch OFF and then back ON before the ECM will retest for the cause of the fault code. The ECM driver is re-enabled at key-on. If the cause if no longer present, the fault code will become inactive and can be cleared.

Note: This fault code will also become active if the priming pump motor stalls. Stall current for the priming pump motor is approximately 9 amperes. A good priming pump typically runs with less than 3 amperes. If the fault code is intermittent, observe the snapshot data priming pump measured current. If current was near 9 amperes when the fault condition occurred, conclude that the rotor has stalled and replace the electric priming pump.

Possible repairs:

1)Replace the fuel lift pump.
2)Repair or replace the engine harness.
3)Replace the ECM.