Engine Coolant Temperature Sensor Out of Range

The engine computer measures the coolant temperature to help manage engine performance. If the reading is too high or too low for a set time, like below 60°F or above 250°F, it triggers this code.

The ECM looks for coolant temperature readings within normal range, typically 160°F to 220°F. If readings exceed this or are below the expected range, it triggers the 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 coolant level — ensure it's within the proper range and not leaking.
2. 22. Inspect the wiring and connectors at the coolant temperature sensor for damage or corrosion — repair as necessary.
3. 33. Use a scan tool to check the coolant temperature reading — it should match the actual temperature (e.g., using a thermometer in the radiator).
4. 44. If the reading is incorrect, replace the coolant temperature sensor if the wiring is good, check for proper resistance (typically 200-1000 ohms at room temp).
5. 55. Clear the code and test drive the vehicle — monitor for code reoccurrence.

• Faulty coolant temperature sensor
• Wiring issue or connector corrosion
• Coolant leaks affecting sensor operation
• ECM calibration issues

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