Case IH 2266 – ENG (Engine Control Module / ECM): Electric Lift Pump for Engine Fuel Supply Voltage too low.

This code is triggered when the Engine Control Module (ECM) detects that the signal circuit for the electric fuel lift pump has dropped below the normal operating voltage range (often reading 0-VDC when commanded ON) or is shorted to a low source/ground. When this occurs, the lift pump cannot supply adequate fuel pressure to the high-pressure injection system, which can result in hard starting, loss of power, or a no-start condition.

• Steiger T4B
• Case IH Magnum Series (215, 225, 245, 250, 275, 280, 305, 310, 335)
• Case IH Steiger Series
• Case IH MX / TG Series

1. 1

   Verify Battery and Charging System: Ensure the tractor's batteries are fully charged and the alternator is outputting correct voltage, as low system voltage can trigger this code.

2. 2

   Inspect the Lift Pump Wiring Harness: Trace the wiring from the Engine ECM to the electric fuel lift pump. Look for chafed wires, melted insulation, or areas where the harness may be shorting to the engine block/ground.

3. 3

   Check Connectors: Disconnect the pigtail at the electric lift pump. Inspect the pins for corrosion, moisture, or pushed-out terminals.

4. 4

   Test Voltage: With a multimeter, probe the lift pump supply circuit with the key turned to the ON position (the ECM usually primes the pump for a short duration at key-on). Verify if the ECM is sending the correct voltage (usually 12V). If voltage is 0V, the issue is likely a short in the harness or a blown fuse/relay.

5. 5

   Test the Lift Pump: If the harness delivers proper voltage but the pump does not run, or if the pump's internal resistance is out of spec (causing a voltage drop), the pump itself has failed.

1. 1

   Disconnect power

   Turn the ignition off and disconnect the negative battery cable to prevent electrical shorts during repair.

2. 2

   Locate the lift pump

   Find the electric fuel lift pump mounted on the intake side of the engine, often integrated with or located near the primary fuel filter/water separator housing.

3. 3

   Repair wiring

   If the diagnostic checks revealed a short to ground in the engine harness, splice and heat-shrink the damaged wires, or replace the affected harness section.

4. 4

   Replace the lift pump

   If the pump has failed, disconnect the electrical connector from the pump. Place a drain pan underneath to catch residual diesel fuel. Disconnect the inlet and outlet fuel lines from the pump. Unbolt the pump bracket from the engine block and remove the faulty pump. Install the new lift pump, torque the mounting bolts to OEM spec, and reconnect the fuel lines.

5. 5

   Reassemble and prime

   Reconnect the electrical connector and the battery. Turn the ignition key to the ON position for 1 minute without starting the engine to allow the new lift pump to prime the fuel system and purge air.

6. 6

   Clear codes

   Use a diagnostic service tool to clear the inactive fault code from the ECM and verify the Check Engine light turns off.