Case IH 3173 (F-110-00) – Engine Control Unit (ECU A-095): Engine coolant temperature has exceeded the warning threshold

The control system monitors the engine coolant temperature via an analog input signal from the Coolant Temperature Sensor (designated as sensor B-016). A critical 3173 warning fault is logged when the engine coolant temperature exceeds 110.0 °C (229.9 °F).

• VESTRUM CVX
• Puma series (130 to 240 CVX)
• Magnum series (180 to 340)
• Maxxum series (110 to 150)
• Steiger series
• Farmall series (85C, 95, 105U, 115U)
• 240 Series Axial-Flow Combines
• 7120 through 9230 rotary harvesters

1. 1

   Check the engine coolant level.

2. 2

   Inspect the radiator, aftercooler, and front cooling packages for blockages (chaff, dirt, or debris).

3. 3

   Verify that the cooling fan is operating correctly.

4. 4

   Check the sensor voltage at the ECU (A-095). If the signal circuit drops below 0.188 V, it indicates the sensor is shorted internally or the signal wire is shorted to ground.

5. 5

   Inspect the wiring harness leading to sensor B-016 for chafing, bare wires, or a disconnected plug.

1. 1

   Safety First

   Shut down the engine and allow it to cool completely. Never open the high-pressure cooling system or loosen fittings while the engine is hot or running, as pressurized coolant can cause severe burns.

2. 2

   Resolve Mechanical Overheating

   If the engine is genuinely overheating, clean the radiator fins, clear any blockages, and top off the coolant to the appropriate level.

3. 3

   Electrical Repair

   If the engine is cool but the fault persists (indicating a sensor failure), locate the B-016 Engine Coolant Temperature Sensor on the engine block.

4. 4

   Inspect Wiring

   Disconnect the wiring harness from the sensor and inspect the pins for corrosion.

5. 5

   Remove Sensor

   Unthread the faulty sensor from the block.

6. 6

   Install Sensor

   Install the new OEM coolant temperature sensor and tighten it to factory specifications. Reconnect the wiring harness.

7. 7

   Clear Codes

   Use the Case IH Electronic Service Tool (EST) to clear the fault code from the ECU's memory, as historical faults may remain stored even after the physical repair is completed.