New Holland 3007 – ECU: Coolant Temperature Signal Exceeds Maximum Range

The Engine Control Unit (ECU) has detected a voltage from the engine coolant temperature sensor that is higher than the maximum expected upper limit (Signal Above Range Max). Because the sensor is a Negative Temperature Coefficient (NTC) thermistor, a high voltage signal typically indicates an open circuit or high resistance fault, which the ECU interprets as an extremely cold, out-of-range temperature. This condition can negatively impact critical engine functions such as fuel injection timing, duration, and cooling fan control.

• W50C
• W60C
• W70C
• W80C
• T7 Series

1. 1

   Check for other logged fault codes, as issues with the sensor power supply could trigger multiple codes simultaneously

2. 2

   Visually inspect the wiring harness and connectors between the coolant temperature sensor and the ECU for damage, corrosion, or loose connections

3. 3

   Perform a sensor resistance test using a multimeter across the sensor's terminals at different temperatures (expected: 2.2kΩ to 3.0kΩ at 20°C/68°F; 250-350Ω at 80°C/176°F). Infinite resistance indicates an open circuit and a faulty sensor

1. 1

   Allow the Engine to Cool

   Ensure the engine is completely cool and the cooling system is not pressurized before beginning work.

2. 2

   Locate the Sensor

   The coolant temperature sensor is typically located on the engine block, often near the thermostat housing.

3. 3

   Perform Diagnostic Checks

   Complete the diagnostic checks listed above to confirm if the sensor or wiring is the issue. A service manual for New Holland W-series compact wheel loaders provides a schematic indicating the coolant temperature signal pin is pin 57 on the ECU connector X-078, with the ground at pin 58.

4. 4

   Repair Wiring

   If the wiring is found to be damaged, repair or replace the affected section of the harness.

5. 5

   Replace the Sensor

   If the sensor is determined to be faulty, place a drain pan beneath it to catch any coolant. Disconnect the electrical connector, carefully unscrew and remove the old sensor, quickly install the new sensor tightened to the manufacturer's specified torque, and reconnect the electrical connector.

6. 6

   Top Off Coolant

   Check the engine coolant level and top it off as necessary to replace any fluid lost during the sensor replacement.

7. 7

   Clear Fault Codes

   Use a diagnostic tool to clear the 3007 fault code from the ECU.

8. 8

   Verify the Repair

   Start the engine and let it run, monitoring the temperature gauge and checking for any new fault codes to ensure the repair was successful.