John Deere 000110.00 – ECU: Engine Coolant Temperature High

The system has detected a dangerously high engine coolant temperature, indicating an issue with the cooling system or the ability to regulate engine temperature effectively. This condition triggers a protective reduction in engine power and may display a 'STOP Engine' warning on the corner post display. If not addressed immediately, it can result in catastrophic engine failure such as warped cylinder heads or engine seizure.

• 7720
• 7820
• 7920
• 8110
• 8130
• 8210
• 8230
• 8310
• 8330
• 8410
• 8430
• 8530
• 5E Series
• 6B Series
• 6E Series
• 6M Series
• 6R Series
• 7R Series
• 8R Series
• 8RX Series
• 9R Series
• 9RX Series
• combines
• cotton pickers
• swathers
• loaders
• excavators
• 3029 series
• 4039 series
• 4045 series
• 6068 series
• 6081 series

1. 1

   Check the engine's coolant level. If the level is low, top it off with the recommended coolant and inspect for any visible leaks.

2. 2

   Visually inspect the radiator and cooling system for any debris, such as dirt, leaves, or crop residue, that could be obstructing airflow. Clean the radiator fins as necessary.

3. 3

   After allowing the engine to cool, pressurize the cooling system to check for leaks. A pressure drop indicates a leak. Also, inspect the de-aeration tank cap for proper sealing.

4. 4

   Observe the coolant recovery tank. If the coolant level in the tank does not fluctuate between a cold and warm engine, it may indicate a leak or low coolant in the pressurized part of the system.

1. 1

   Test the Engine Coolant Temperature (ECT) Sensor

   Disconnect the sensor's electrical connector and measure the resistance across the terminals when the engine is cold. Start the engine, let it warm up, and measure again at operating temperature. Resistance should decrease smoothly as temperature increases (e.g., ~2200-3000 Ω at 20°C/68°F to 250-350 Ω at 80°C/176°F). An open circuit or no change in resistance indicates a faulty sensor.

2. 2

   Inspect Wiring

   Check the wiring harness and connector for the ECT sensor for any signs of damage, corrosion, or loose connections.

3. 3

   Check the Thermostat

   Inspect the thermostat to ensure it is not stuck closed, which prevents coolant from circulating to the radiator and causes overheating. Replace if faulty.

4. 4

   Flush the Cooling System

   If the coolant is old or contaminated, drain the old coolant. Fill the system with a John Deere-approved cooling system cleaner and clean water, run the engine for about 15 minutes, drain, flush with clean water, and refill with John Deere Cool-Gard II mixed with distilled or demineralized water.

5. 5

   Replace Faulty Components

   Based on the diagnostic tests, replace the engine coolant temperature sensor or the thermostat. Ensure you inspect and replace associated O-rings or seals to guarantee a proper seal.