New Holland ENG 144 – ENGINE Controller (Engine ECU / ECM): Coolant Temperature Sensor voltage is too high.

This code is triggered when the Engine Control Module (ECM) detects that the signal voltage from the Engine Coolant Temperature (ECT) sensor has exceeded the normal operating range. This almost always indicates an open circuit, typically caused by a disconnected sensor, a broken wire in the harness, or a sensor that has failed internally.

• T6000
• T8 series
• T8.275
• T8.300
• TM series
• TM120
• TM130
• TM140
• TM155
• TM175
• TM190
• TV140
• MX Magnum series
• CR9090
• CX8080
• CX8090
• CNH backhoes
• CNH loaders
• CNH excavators
• CNH telehandlers

1. 1

   Visually inspect the coolant temperature sensor and connector for backed-out pins, corrosion, moisture, or a loose connection.

2. 2

   Inspect the wiring harness between the sensor and the Engine ECM for chafed, broken, or melted wires that could cause an open circuit or short to a high-voltage source.

3. 3

   Perform a sensor resistance test with a multimeter. Expected values: 30k-36k ohms at 0°C, 9k-11k ohms at 25°C, 600-675 ohms at 100°C. An 'OL' reading indicates internal failure.

4. 4

   With the key ON and sensor disconnected, check the harness side for the 5V reference signal from the ECM to rule out wiring or ECM faults.

1. 1

   Prep the Machine

   Park the machine on a level surface, turn off the engine, remove the key, and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Locate the Sensor

   Find the coolant temperature sensor on the engine block or thermostat housing.

3. 3

   Relieve Pressure

   Ensure the engine is completely cool. Slowly loosen the radiator cap to relieve any residual cooling system pressure, then retighten it. (This minimizes coolant loss when the sensor is removed).

4. 4

   Remove the Sensor

   Disconnect the electrical harness from the sensor. Use a deep socket or wrench to unthread the sensor from the housing. Have a shop rag or catch pan ready, as a small amount of coolant will leak out.

5. 5

   Install the New Sensor

   Thread the new coolant temperature sensor into the housing. Tighten it to the manufacturer's specified torque (do not overtighten, as the brass threads can break).

6. 6

   Reconnect

   Plug the electrical connector back into the sensor until it clicks.

7. 7

   Refill and Test

   Top off the engine coolant to replace any that was lost. Reconnect the battery. Start the engine and verify that the dashboard temperature gauge reads correctly and the ENG 144 fault code has cleared.