Engine Coolant Temperature Sensor Out of Range
The engine coolant temperature sensor is reporting temperatures outside the expected range.
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What it means (plain English)
The engine coolant temperature sensor measures how hot the engine is running. If it's too cold or too hot, the computer gets confused because it's not seeing expected temperatures.
What the computer is actually seeing
The engine control module (ECM) expects coolant temperatures to range from 180°F to 220°F (82°C to 105°C) during normal operation. Values outside this range trigger a fault code.
What a healthy reading looks like
Coolant temperature should be between 180°F and 220°F (82°C and 105°C). If readings exceed 250°F (121°C) or drop below 140°F (60°C), that indicates a problem.
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 coolant level. Add if low.
- 22. Inspect the wiring and connectors on the coolant temperature sensor for damage or corrosion.
- 33. Test the resistance of the coolant temperature sensor at room temperature; it should read about 2.5k ohms at 70°F (21°C).
- 44. Start the engine and monitor the sensor reading with a scan tool. Ensure it changes with engine temperature.
- 55. If the sensor reading is fixed or shows out-of-range values, replace the coolant temperature sensor.
- 66. If issues persist after sensor replacement, check the engine thermostat and wiring harness for shorts or opens.
Common causes
- Faulty coolant temperature sensor
- Wiring harness issues (shorts, opens)
- Coolant leaks affecting sensor readings
- Faulty engine thermostat
- Contaminated or low coolant level
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this fault code?
It's generally drivable but address it soon to prevent overheating or poor performance.
Will this code come back after I clear it?
If the underlying issue isn't fixed, yes, it will return.
Why does this code pair with other temperature codes?
Temperature sensors can interact; if one fails, it may cause or reveal issues in others.
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