Engine Coolant Temperature Above Normal Operating Range
The engine coolant temperature is higher than expected during operation.
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What it means (plain English)
The engine's computer thinks the coolant is too hot, which could be from a bad sensor, low coolant, or overheating issues.
What the computer is actually seeing
The engine control module (ECM) monitors coolant temperature through a sensor, expecting it to stay around 180°F to 220°F (82°C to 104°C) when running. If the temperature exceeds about 230°F (110°C), it triggers this code.
What a healthy reading looks like
Normal coolant temperature should be between 180°F and 220°F (82°C to 104°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 coolant level in the reservoir. Is it low? If yes, refill and retest. If not, go to step 2.
- 22. Inspect the engine coolant temperature sensor connector and wiring for damage. Is it intact? If yes, go to step 3.
- 33. Use a scan tool to check the actual coolant temperature reading. Is it above 230°F (110°C)? If yes, go to step 4. If no, replace the sensor.
- 44. Check the operation of the thermostat. Is it stuck closed? If yes, replace the thermostat. If it's functioning, go to step 5.
- 55. Inspect the cooling system for blockages and the water pump for proper operation. Are there any obstructions or is the pump failing? If yes, resolve those issues. If no, further diagnostic may be required.
Common causes
- Faulty engine coolant temperature sensor
- Low coolant level
- Thermostat stuck closed
- Cooling system blockage
- Water pump failure
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
No, it may lead to overheating and engine damage.
Will this code come back after fixing it?
If you fix the underlying cause, the code should not return.
Why does this code pair with others?
This code often appears with others linked to temperature or coolant flow issues.
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