Engine Coolant Temperature Sensor Circuit High
The engine coolant temperature sensor is reporting a high signal.
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What it means (plain English)
The coolant temperature sensor is reading a voltage that suggests the engine is overheating, even if it's not actually too hot.
What the computer is actually seeing
The engine control module expects a voltage range from the coolant temperature sensor, typically around 0.5V to 4.5V, indicating temperatures from -40°C to 125°C. A high signal often exceeds 4.5V.
What a healthy reading looks like
Voltage should be between 0.5V (cold) and 4.5V (hot). If readings are above 4.5V, troubleshoot.
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 engine coolant level; fill if low, then retry scanning for codes.
- 2Inspect wiring and connector at the coolant temperature sensor for damage or corrosion.
- 3Measure voltage at the coolant temperature sensor connector. It should be within the expected values. If over 4.5V, check for shorts to power.
- 4Test the coolant temperature sensor using a scan tool. Compare the reading with actual coolant temperature. If readings don’t match, replace the sensor.
- 5If sensor is replaced and code persists, check for a short in the harness or possible ECM issues.
Common causes
- Short in the wiring to the coolant temperature sensor
- Faulty coolant temperature sensor
- Corrosion or poor connection at the sensor or ECM
- Incorrect coolant levels affecting sensor readings
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; it's best to fix it soon as it may affect performance.
Will this code come back after clearing?
Yes, especially if the underlying issue isn't resolved.
Why does this code often pair with SPN 110?
SPN 110 is also related to coolant temperature and may indicate a broader cooling system issue.
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