Case IH 3443 (F-519867-31) - ECU – Engine Control Unit (ECU / ECM): Torque limitation due to excessive coolant temperature

The engine coolant temperature has exceeded the maximum safe operating threshold. To prevent catastrophic engine damage from overheating, the control module actively derates the engine, limiting the maximum torque output and reducing locomotive performance.

• VESTRUM CVX
• 240 Series Axial-Flow Combines (7240, 8240, 9240)
• 7230
• 8230
• 9230
• AFX series
• Magnum series (180-380)
• Steiger series (350-620)
• Farmall series (40-50, 85C-120U)
• Maxxum
• Puma
• Optum
• Patriot 4440

1. 1

   Check the radiator and cooling package for blockages (chaff, dirt, or debris).

2. 2

   Verify the engine coolant level and check the coolant condition.

3. 3

   Visually inspect the wiring harness and connectors leading to the Engine Coolant Temperature (ECT) sensor for damage, bent or dislocated pins, corroded terminals, or broken wires.

4. 4

   Flex the harness while monitoring the display to check for intermittent shorts to ground or power.

5. 5

   Use a multimeter (ohmmeter) to measure the resistance of the ECT sensor, or use a diagnostic scanner to read the live temperature data.

1. 1

   Address Physical Overheating

   If the engine is genuinely overheating, thoroughly clean the radiator, ensure the cooling fan is operating correctly, and top off the coolant with the approved Case IH extended-life coolant.

2. 2

   Locate the ECT Sensor

   If diagnostics point to a failed sensor, locate the Engine Coolant Temperature sensor. It is typically threaded into the cylinder head near the thermostat housing, the upper radiator hose outlet, or above the injection pump depending on the specific engine model.

3. 3

   Remove the Faulty Sensor

   Disconnect the electrical connector from the sensor. Carefully unscrew the sensor from the housing (have a catch pan ready, as some coolant may leak out).

4. 4

   Install the New Sensor

   Thread the new OEM replacement sensor into the housing and tighten to the manufacturer's specified torque.

5. 5

   Reconnect and Refill

   Reconnect the wiring harness. Top off any lost coolant.

6. 6

   Clear Codes

   Turn the key on and use a diagnostic tool to clear the inactive 3443 fault code from the ECU memory. Run the machine to operating temperature to verify the fix.