Case IH 3665 – Engine Control Unit (ECU): Desired EGR Valve Position Can Not Be Reached (EGR Valve Sticks, Position Sensor Mismatched)

The engine controller is commanding the Exhaust Gas Recirculation (EGR) valve to a specific position, but the feedback from the valve's position sensor does not match the commanded position. This is typically caused by the EGR valve physically sticking, being blocked by carbon buildup, or a failure within the valve's internal position sensor.

• skid steer
• Farmall 105C
• Farmall 115C
• Farmall 105U
• Farmall 115U
• Farmall 100CL
• Farmall 110N
• Farmall 110V
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• Backhoe 580N
• Backhoe 580SN
• Backhoe 590SN
• Compact Wheel Loader 21F
• Compact Wheel Loader 121F
• Compact Wheel Loader 221F
• Compact Wheel Loader 321F
• Steiger

1. 1

   Check battery voltage to ensure stable system voltage, as low voltage can cause erratic sensor readings or deactivate the power supply stage diagnosis.

2. 2

   Inspect the wiring harness and connector at the EGR valve for signs of corrosion, short circuits, or open loads.

3. 3

   Inspect the EGR valve for heavy soot or carbon buildup that could cause the valve to stick in the closed or open position.

4. 4

   Perform a software reset using the Case IH Electronic Service Tool (EST) to attempt to restore the engine's self-learning parameters before replacing hard parts.

1. 1

   Gain Access

   Depending on the specific machine (tractor vs. skid steer), remove any engine cowlings or exhaust heat shields blocking access to the EGR system. Note: On some F5C engine configurations, accessing the EGR system may require removing the valve cover and the overhead holding the rocker arm unit.

2. 2

   Remove the EGR Valve

   Unbolt the EGR control valve from the exhaust/intake manifold assembly. Recover and discard the old mounting gaskets.

3. 3

   Clean the Port

   Inspect the manifold ports for excessive carbon buildup and clean them carefully to ensure the new valve will not immediately jam.

4. 4

   Install the New Valve

   Install the replacement EGR valve using new gaskets. Torque the fastening screws to the OEM specifications outlined in the F5C service manual.

5. 5

   Reassemble

   Reinstall any removed covers, rocker assemblies, or heat shields.

6. 6

   ECU Configuration

   Connect the Case IH Electronic Service Tool (EST). You must follow the service tool procedure to 'Reset ECU data (EGR valve)' and restore the engine self-learning parameters so the ECU can learn the new valve's position sensor sweeps.

7. 7

   Test

   Run the engine and verify that fault code 3665 does not return. If the fault persists after replacing the valve and resetting parameters, the Engine Controller/EDC itself may need to be replaced.