Engine Coolant Temperature Too High
The engine coolant temperature exceeds the normal operating range.
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What it means (plain English)
The engine is running hotter than it should, often over 220°F (104°C), which can lead to overheating and damage.
What the computer is actually seeing
The engine control module (ECM) is receiving signals from the coolant temperature sensor indicating a temperature over 220°F (104°C).
What a healthy reading looks like
Normal coolant temperature is between 180°F (82°C) and 210°F (99°C).
Guided diagnostic — the DiagCoach way
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.
- 11. Check the engine coolant level. If low, top it off and monitor.
- 22. Inspect for any visible coolant leaks in hoses, radiator, and engine block.
- 33. Test the operation of the thermostat by checking engine temperature rise during idle. If temperature exceeds 210°F (99°C) without the thermostat opening, replace it.
- 44. Check if the cooling fans are operational by turning on the AC and observing fan engagement.
- 55. Use a scan tool to check the coolant temperature sensor readings. Compare it with actual temperature values; replace the sensor if discrepancies are found.
Common causes
- Low coolant level due to a leak
- Faulty thermostat stuck closed
- Blocked radiator or cooling passages
- Cooling fan not operating
- Malfunctioning coolant temperature sensor
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code present?
No, driving with an overheated engine can cause serious damage and should be addressed immediately.
Will it come back after repairs?
If repairs are done correctly and the underlying issues are fixed, it should not come back.
Why does this code pair with low coolant?
Low coolant can cause the engine to overheat, triggering this fault code.
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