PACCAR PX-9 CM2350 (2013-17) 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

Reason:
Electric Lift Pump for Engine Fuel Supply Circuit – Voltage Above Normal or Shorted to High Source. High voltage or open circuit detected at the fuel lift pump signal circuit.

Effect:
Engine may not start or may be difficult to start.

Circuit Description:
The fuel lift pump circuit is a discrete output in the engine control module (ECM) that controls the electric fuel lift pump. The lift pump is grounded in the ECM.

Component Location:
The fuel lift pump is mounted on the intake side of the engine.

Conditions for Running the Diagnostics:
This diagnostic runs when the keyswitch is initially turned to the ON position.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the fuel lift pump signal circuit was detected to be 0-VDC when the signal is turned ON by the engine control module (ECM).

Action Taken When the Fault Code is Active:
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, and leave the key in the ON position 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) 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:
N/A

Possible Causes:
1) A short circuit to ground in the engine harness
2) A malfunctioning fuel lift pump