Massey Ferguson 000110.03 – ECU: Coolant Temperature Signal Voltage High

The Engine Control Unit (ECU) has detected that the voltage signal from the engine coolant temperature sensor is above the expected maximum threshold. This typically indicates an open circuit or high resistance in the sensor's wiring or the sensor itself, which prevents the 5-volt reference signal from being pulled down to the correct level. This fault can lead to incorrect engine performance adjustments, potential overheating issues, or cause the engine cooling fan to run continuously.

• 4607 M
• 4608
• 4609
• 4609 M
• 4610
• 4610 M
• 4707
• 4708
• 4708 M
• 4709
• 4709 M
• 4710
• 4710 M
• 5425
• 5435
• 5450 T3
• 5460
• 5465
• 5470
• 5475
• 5480
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 5708
• 5709
• 5710
• 5711
• 5712
• 5713
• 6612
• 6613
• 6614
• 6615
• 6616
• 6711
• 6712
• 6713
• 6714
• 6715
• 6716
• 6718
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714 S
• 7715 S
• 7716 S
• 7718 S
• 7719 S
• 7720 S
• 7722 S
• 7724 S
• 7726 S
• 8727 S
• 8730 S
• 8732 S
• 8735 S
• 8737 S
• 8740 S
• 1200 Series
• 1400 Series
• 1500 Series
• 1600 Series

1. 1

   Visually inspect the wiring harness and connector leading to the coolant temperature sensor for frayed or broken wires, corrosion in the pins, or loose connections.

2. 2

   Check for power and ground at the sensor connector (with the sensor disconnected and ignition ON, engine OFF). Verify there is approximately a 5V reference signal from the ECU on one terminal and a good ground on the other.

3. 3

   Test the sensor's resistance using a multimeter set to Ohms. Resistance should be high when cold (e.g., 2,200-3,000 ohms at 20°C) and low when hot (e.g., 250-350 ohms at 80°C). An infinite reading indicates an open circuit and a faulty sensor.

4. 4

   Inspect the wiring harness for a short to power, looking for areas where the signal wire might be chafed or melted against a voltage-carrying wire.

1. 1

   Ensure Safety

   Park the tractor on a level surface, turn off the engine, and engage the parking brake. Allow the engine to cool completely before working on the cooling system to prevent burns.

2. 2

   Disconnect the Battery

   Disconnect the negative battery terminal as a safety precaution.

3. 3

   Locate and Disconnect the Sensor

   Identify the coolant temperature sensor on the engine and disconnect its electrical connector.

4. 4

   Drain Coolant (If Necessary)

   Depending on the sensor's location, you may need to partially or fully drain the engine coolant to avoid spillage when the sensor is removed. Place a clean container under the radiator drain petcock.

5. 5

   Remove the Old Sensor

   Using the appropriate wrench or socket, carefully unscrew and remove the old sensor from the engine.

6. 6

   Install the New Sensor

   Compare the new sensor to the old one to ensure it is the correct part. Apply a small amount of thread sealant to the threads of the new sensor if not already applied. Screw the new sensor into place and tighten it to the manufacturer's specified torque. Do not overtighten.

7. 7

   Reconnect and Refill

   Reconnect the electrical connector to the new sensor. Refill the cooling system with the correct type and amount of coolant. Reconnect the negative battery terminal.

8. 8

   Clear Fault Codes and Test

   Start the engine and let it run, checking for any leaks. Use a diagnostic tool to clear the 000110.03 fault code. Monitor the engine temperature gauge and live data to ensure the new sensor is providing a correct reading.