Case IH 19893 – Engine Control Unit (ECU): Water pump inlet pressure is too high

This fault condition indicates that the sensor monitoring the coolant pressure at the inlet side of the water pump is reporting a pressure value (or a voltage signal) that exceeds the maximum allowable threshold programmed into the control module. This can be caused by a physical overpressure condition in the cooling system or an electrical fault.

• Tier 4b
• Case IH 240 Series Axial-Flow Combines (7240, 8240, 9240)
• Case IH Magnum tractors
• Case IH Steiger tractors

1. 1

   Connect an electronic service tool to the diagnostic port and monitor the live data for the Water Pump Inlet Pressure Sensor. Note if the pressure reads artificially high even when the engine is off (indicating an electrical/sensor fault).

2. 2

   Inspect the wiring harness between the water pump inlet pressure sensor and the ECU. Check for a short to power on the sensor signal wire.

3. 3

   Check the sensor connector for corrosion, water intrusion, or damaged pins.

4. 4

   Check for physical blockages in the cooling system, such as a collapsed radiator hose or a stuck-closed thermostat that could cause abnormal pressure spikes at the pump inlet.

5. 5

   Ensure the cooling system is not overfilled or improperly pressurized.

1. 1

   Depressurize the System

   Ensure the engine is completely cool. Slowly remove the coolant reservoir cap to relieve any residual pressure in the cooling system.

2. 2

   Disconnect the Battery

   Disconnect the negative battery terminal to prevent electrical spikes during sensor replacement.

3. 3

   Access the Sensor

   Locate the water pump inlet pressure sensor on the engine block near the water pump housing.

4. 4

   Remove the Sensor

   Disconnect the electrical harness connector. Use a wrench to carefully unthread the pressure sensor from the housing. Have a catch pan ready, as a small amount of coolant may leak out.

5. 5

   Install the New Sensor

   Thread the new sensor into the housing. Torque it to the specifications outlined in the FPT/Case IH engine service manual (do not overtighten, as this can damage the brass threads).

6. 6

   Reconnect and Refill

   Reconnect the electrical harness. Top off the engine coolant to the appropriate level.

7. 7

   Clear Codes and Test

   Reconnect the battery, connect the diagnostic service tool, and clear the active/stored fault codes. Start the engine, let it reach operating temperature, and verify that the live pressure readings are within normal limits and the code does not return.