Engine Coolant Temperature Too High
Indicates that the engine coolant temperature is exceeding normal limits.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine computer is seeing that the coolant temperature is too high, usually over 239°F (115°C), which can lead to overheating.
What the computer is actually seeing
The engine control module (ECM) monitors the engine coolant temperature sensor. When the temperature exceeds the threshold value, it triggers this fault code.
What a healthy reading looks like
Normal coolant temperature should range between 185°F to 220°F (85°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.
- 1Check the coolant level in the reservoir; it should be between the 'min' and 'max' marks. If low, add coolant and monitor for leaks.
- 2Inspect the wiring and connector on the coolant temperature sensor for any damage or corrosion.
- 3Test the coolant temperature sensor using a multimeter; at 200°F (93°C), it should read approximately 0.5V. If off, replace the sensor.
- 4Verify the thermostat is functioning by checking if the engine warms up properly; if it stays cold, replace the thermostat.
- 5Check the radiator for blockages or debris that could restrict airflow.
Common causes
- Low coolant levels due to leaks
- Faulty coolant temperature sensor
- Blocked radiator or cooling system
- Worn water pump
- Thermostat stuck closed
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
No, it's not safe to drive as overheating can cause severe engine damage.
Will this code come back after I clear it?
If the underlying issue isn't fixed, yes, the code will likely return.
Why does this code pair with others?
Multiple codes can activate due to a common fault, like cooling system issues affecting several sensors.
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