Engine Coolant Temperature Too High

The temperature sensor for the engine coolant is detecting a temperature above what the engine is designed to handle, usually over 240°F (115°C). This means the engine is likely overheating, which can cause severe damage if not addressed immediately.

The ECU interprets the temperature readings from the coolant temperature sensor. If the sensor reports a temperature significantly higher than the normal operating range, it triggers this fault 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 the engine coolant level: ensure it's within the operating range. If low, refill and check for leaks.
2. 22. Inspect the wiring and connector to the coolant temperature sensor for damage or corrosion. Repair as necessary.
3. 33. With the engine at idle, use a scanner to monitor the coolant temperature reading. Is it above 240°F (115°C)? If yes, continue to step 4; if no, suspect sensor failure or erratic readings.
4. 44. Check for coolant flow: feel the upper and lower radiator hoses after the engine has warmed up. Are both hoses hot? If not, the thermostat or water pump may be faulty.
5. 55. Inspect the radiator for blockage or debris. Clear any obstructions found. Test operation again. Is the code still present?

• Low coolant level due to leaks
• Failed thermostat
• Malfunctioning water pump
• Blocked radiator or cooling passages

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