Case IH 2266 – ENG (Engine Controller / Engine ECU): Electric Lift Pump for Engine Fuel Supply Voltage too low

The Engine Control Module has detected a low signal voltage at the fuel lift pump circuit. The circuit voltage is below the normal operating range, indicating a potential short to a low source (ground) or an open circuit in the lift pump control signal. This condition can cause the engine to be difficult to start, run poorly, or fail to run due to inadequate fuel supply pressure.

• MX Magnum
• TG Series
• Steiger
• Puma
• CVX series
• Axial-Flow Combine 2344
• Axial-Flow Combine 2366
• Axial-Flow Combine 2377
• Axial-Flow Combine 2388
• Axial-Flow Combine 2577
• Axial-Flow Combine 2588

1. 1

   Inspect the wiring harness and connectors between the Engine ECU and the electric fuel lift pump for physical damage, chafing, corrosion, or pushed-out pins.

2. 2

   With the key in the ON position, use a multimeter to check the supply voltage at the lift pump connector.

3. 3

   Test the fuel lift pump control signal circuit for a short to ground (which triggers the 'Voltage too low' condition).

4. 4

   Check the lift pump relay and fuses. If the wiring is intact and providing the correct voltage/ground, test the internal circuitry of the electric lift pump itself for a short.

1. 1

   Disconnect Power

   Disconnect the negative battery terminal to prevent electrical spikes during repair.

2. 2

   Locate the Pump

   Locate the electric fuel lift pump (typically mounted on the engine block or along the chassis fuel lines, depending on the machine).

3. 3

   Wiring Repair (If Applicable)

   If diagnostics revealed a short to ground in the harness, repair or splice the damaged section of the wiring and secure it in a protective loom.

4. 4

   Remove the Lift Pump (If Failed)

   Disconnect the electrical connector from the lift pump. Place a catch pan underneath to catch spilled diesel fuel. Disconnect the inlet and outlet fuel lines from the pump. Unbolt the pump bracket/housing and remove the faulty unit.

5. 5

   Install the New Pump

   Mount the new electric lift pump and tighten the bolts to OEM torque specs. Reconnect the fuel lines, ensuring any copper washers or O-rings are replaced to prevent air leaks. Plug in the electrical connector.

6. 6

   Prime and Clear

   Reconnect the battery. Turn the ignition key to the ON position (without cranking) for several seconds to allow the new electric lift pump to prime the fuel system. Use a diagnostic scan tool to clear fault code 2266 from the Engine ECU.