Case IH 3665 – ECU: Permanent Governor Deviation For Valve

Fault code 3665 triggers when the engine's control system commands the Exhaust Gas Recirculation (EGR) valve to move to a specific position, but the valve fails to reach it. The underlying condition is typically caused by the EGR valve physically sticking due to carbon buildup or a mismatch/failure in the EGR position sensor.

• Farmall
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• Maxxum
• Puma
• Steiger

1. 1

   Clear the code and operate the machine to see if it returns. If the failure isn't present again after a short time, no reaction is needed.

2. 2

   Inspect the wiring harness and connector going to the EGR valve for chafing, corrosion, or loose pins that could cause a sensor mismatch.

3. 3

   Use the Case IH Electronic Service Tool (EST) to restore the engine's self-learning parameters for the EGR valve circuit.

4. 4

   Remove the EGR valve and inspect it for heavy soot or carbon buildup that could be causing the valve to stick mechanically.

1. 1

   Preparation

   Turn off the engine, remove the key, and disconnect the negative battery cable. Allow the engine and exhaust components to cool completely.

2. 2

   Access the EGR Valve

   Locate the EGR valve assembly on the engine (typically routing from the exhaust manifold to the intake).

3. 3

   Removal

   Disconnect the electrical connector from the EGR valve actuator. Remove the mounting bolts and carefully detach the EGR valve from the manifold.

4. 4

   Cleaning (Optional)

   If the valve is only lightly stuck, attempt to clean the carbon deposits using an EGR-safe solvent. Ensure the valve flap moves freely. If the position sensor is internally failed, cleaning will not work.

5. 5

   Installation

   Install the new EGR valve using a new gasket. Torque the mounting bolts to OEM specifications and reconnect the electrical harness.

6. 6

   ECU Calibration

   Reconnect the battery. You must use the Case IH Electronic Service Tool (EST) to run the Reset ECU data (EGR valve) procedure so the Engine Controller can learn the new valve's end-stops.

7. 7

   Final Verification

   Start the engine and run it up to operating temperature. If the fault code 3665 persists after replacing the EGR valve and resetting the parameters, the OEM manual states to replace the Engine Controller.