Case IH 3474 – Engine Control Unit (ECU) / EDC (Electronic Diesel Control): Water pump actuator reports an over temperature error

The electrically controlled coolant pump has detected an internal over-temperature condition. The actuator's internal motor controller monitors its own temperature and power stage; if it detects excessive heat—often due to a mechanical bind, excessive current draw, or a failing internal circuit—it broadcasts this error over the CAN bus.

• Magnum series
• Steiger series
• Optum series
• Axial-Flow 240 series combines

1. 1

   Check the CAN Configuration: Verify the communication status of the water pump actuator via the diagnostic service tool to ensure the EDC is receiving the correct data length and status signals.

2. 2

   Inspect Wiring and Connectors: Check the wiring harness and the connector at the water pump for loose contacts, corrosion, or damage. A loose contact on the actuator power supply can cause high resistance, leading to excessive heat and sporadic re-initializations.

3. 3

   Check for Mechanical Binding: Verify if the water pump is mechanically stalled or binding (Motor Stall status [0001]). A seized impeller will cause the electric motor to draw maximum current, resulting in an over-temperature error.

4. 4

   Verify Power Supply: Check for short circuits to the battery or ground on the output power stage, which can also trigger related temperature and electrical errors.

1. 1

   Preparation

   Turn off the engine, allow it to cool completely, and disconnect the machine's battery.

2. 2

   Drain Coolant

   Place a clean drain pan under the engine and drain the cooling system.

3. 3

   Remove Accessories

   Depending on the specific engine model (e.g., Cursor 9, N67), remove the serpentine drive belt and any interfering intake piping or shrouds to access the water pump.

4. 4

   Disconnect Actuator

   Unplug the electrical connector from the water pump actuator.

5. 5

   Remove the Pump

   Disconnect the coolant hoses attached to the pump. Remove the mounting bolts securing the water pump assembly to the engine block and remove the pump.

6. 6

   Clean Mating Surfaces

   Thoroughly clean the engine block mating surface, ensuring no old gasket material remains.

7. 7

   Install New Pump

   Install the new water pump actuator with a new gasket/O-ring. Torque the mounting bolts to the OEM specifications outlined in the specific engine service manual.

8. 8

   Reassembly

   Reconnect the coolant hoses, plug in the electrical connector, and reinstall the drive belt and any removed components.

9. 9

   Refill and Bleed

   Refill the cooling system with the specified Case IH / FPT approved coolant.

10. 10

    Clear Codes and Test

    Reconnect the battery. Use a diagnostic tool to clear the fault codes. Start the engine, allow it to reach operating temperature, check for leaks, and verify that the water pump actuator is responding to ECU commands without throwing the over-temperature code.