Case IH 3473 – Engine ECU: Water pump actuator reports a system error

The electrically controlled coolant pump (PWM actuator) has detected a general system failure. The internal controller monitors its own operation and triggers this code for Motor Stall, Motor Fail, Motor Controller Over/Under Current, Motor Controller Over/Under Voltage, Motor Over Temperature, or Motor not at Target Speed.

• Axial-Flow Combines 240 Series (7240, 8240, 9240)
• Axial-Flow Combines 6130, 6140, 6150, 7130
• Patriot Sprayers 4430 (Tier 4)
• Steiger / Magnum Tractors

1. 1

   Check for accompanying CAN timeout errors or wrong data length codes (e.g., CAN-Receive-Frame of WPC2EDC) indicating a broken or disconnected CAN line

2. 2

   Inspect the wiring harness to the water pump actuator for a short circuit to the battery, a short circuit to ground, or loose contacts on the actuator power supply

3. 3

   Check if the water pump is physically sticking or experiencing abnormal friction, which would cause a Motor Stall status

4. 4

   Verify that the machine is not experiencing high battery voltage or high ECU temperatures, which can trigger controller over-voltage or over-temperature errors

1. 1

   Inspect Electrical Connections

   Disconnect the harness at the water pump actuator. Inspect the pins for corrosion, moisture, or pushed-back terminals.

2. 2

   Test the Harness

   Use a multimeter to verify proper voltage supply, ground, and CAN Bus continuity between the Engine ECU and the water pump actuator connector. Repair any wiring faults found.

3. 3

   Check for Mechanical Failure

   If the wiring is intact, attempt to turn the water pump manually (if accessible) to check for severe binding or sticking.

4. 4

   Replace the Component

   If the wiring and power supply are good, but the actuator continues to report a system error (internal controller failure, over-current, or motor fail), the electrically controlled water pump assembly must be replaced.

5. 5

   Clear and Retest

   After installing the new water pump, clear the fault codes from the Engine ECU. Run the engine and verify that the coolant pump reaches its target speed without triggering a slow response or deviation error.