Case IH 3443 – Engine Control Module (ECM / ECU): Torque limitation due to excessive coolant temperature

This is a protective derate (performance limitation) condition. When the engine's coolant temperature exceeds safe operating parameters, the system automatically reduces engine power (torque) to prevent catastrophic overheating and internal engine damage. The code itself is an informational confirmation that a temporary power limitation is active due to the high temperature.

• Axial-Flow Combines 240 Series (7240, 8240, 9240)
• Farmall
• Puma
• Magnum

1. 1

   Check coolant levels in the radiator and expansion tank to ensure they are filled to the proper levels with the correct OEM coolant.

2. 2

   Inspect the cooling package (rotary screen, radiator fins, and oil coolers) for blockages from chaff, dust, and debris.

3. 3

   Test the coolant temperature sensor and its wiring harness for physical damage, corrosion, or a short circuit that might send a falsely high reading to the ECM.

4. 4

   Check the thermostat(s) to ensure they are opening at the correct temperature (typically 203°F / 95°C).

5. 5

   Inspect the water pump for weep-hole leaks, bearing play, or a slipping drive belt that would prevent proper coolant circulation.

1. 1

   Clean the Radiator

   Use compressed air to blow out the radiator and cooling package from the inside out. If the code clears after cleaning and running the machine under load, no further repair is needed.

2. 2

   Replace the Coolant Temperature Sensor (if faulty)

   Locate the sensor on the engine block or thermostat housing. Disconnect the 2-pin wiring harness connector. Unthread the old sensor (have a catch pan ready for minor coolant loss). Thread in the new sensor and reconnect the harness.

3. 3

   Replace the Thermostat (if stuck closed)

   Drain the coolant to a level below the thermostat housing. Remove the bolts securing the thermostat housing cover. Remove the old thermostat(s) and clean the mating surfaces. Install the new thermostat(s) and a new gasket, then torque the housing bolts to OEM spec.

4. 4

   Replace the Water Pump (if failing)

   Drain the cooling system completely. Remove the serpentine/drive belt from the water pump pulley. Unbolt the water pump flange from the engine block. Clean the block surface thoroughly. Install the new water pump using a new O-ring/gasket.

5. 5

   Refill and Bleed

   Refill the system with Case IH-approved coolant. Start the engine, let it reach operating temperature, and bleed any trapped air from the system.

6. 6

   Clear Codes

   Use an electronic service tool to clear the 3443 code from the ECM and test the machine under load.