Cummins ISX12 CM2250 (2010-12) Fault Code: 2266 (HD) PID: SID 126 SPN: 1075 FMI: 4 Electric Lift Pump for Engine Fuel Supply Circuit- Voltage Below Normal or Shorted to Low source

Circuit Description
The fuel lift pump relay is controlled by the ECM, and provides power to the fuel lift pump.

Component Location
The fuel lift pump relay is installed in the engine wiring harness near the ECM. The fuel lift pump is mounted on the intake side of the engine.

Conditions for Running the Diagnostics
This diagnostic runs during the first 1 minute after initial key ON, when the fuel lift pump is being commanded to run.

Conditions for Setting the Fault Codes
The engine fuel lift pump relay circuit is detected to be 0-VDC when the signal is turned on by the ECM and must be at system voltage.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
The engine fuel lift pump will be disabled.
Conditions for Clearing the Fault Code
Perform a key cycle, and leave the key switch in the ON position for at least 2 minutes.
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.
The Reset All Faults command in INSITE? electronic service tool can be used to clear active and inactive faults.

Shop Talk
This fault code becomes active whenever the ECM detects a short circuit to ground or high current in the electric fuel lift pump relay circuit.

Possible Cause:
1) Fuel Lift Pump relay failure
2) Engine Harness
3) ECM calibration