Engine Over Temperature

The engine's internal temperature is too high, which can cause serious damage if not addressed.

The engine control unit monitors temperature through a coolant temp sensor; when it sees values above 240°F (116°C), it sets this code.

Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.

1. 11. Check the coolant level in the reservoir. If low, refill and retest. Decision point: Did the code reset? If so, monitor for leaks.
2. 22. Inspect for visible coolant leaks around hoses and radiator. Decision point: Are there leaks? If yes, fix leaks and test drive.
3. 33. Test the thermostat operation by removing it and placing it in hot water. It should open around 195°F (91°C). If it doesn't open, replace it. Decision point: Did replacing the thermostat clear the code?
4. 44. Check coolant temperature sensor resistance with a multimeter. At 200°F (93°C), it should read about 0.5k to 1.5k ohms. If out of range, replace sensor. Decision point: Is the sensor functioning correctly?
5. 55. Inspect the radiator for blockages or debris, ensuring proper airflow. Clean if necessary. Decision point: Did clearing blockages improve cooling?

• Low coolant level
• Faulty thermostat
• Coolant leaks
• Faulty coolant temperature sensor
• Blocked radiator

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