Engine Coolant Temperature Sensor Out of Range
Indicates the engine coolant temperature sensor is reporting a value that is out of the expected range.
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What it means (plain English)
The engine coolant temperature sensor measures how hot the coolant is. If it's too high or too low, the computer thinks something is wrong and gets a weird reading, making it act up.
What the computer is actually seeing
The engine control module (ECM) expects the coolant temperature to be between approximately 185°F and 220°F during normal operation. If the reading goes below 140°F or above 260°F, it triggers this fault.
What a healthy reading looks like
Normal coolant temperature range is between 185°F to 220°F (85°C to 104°C). Malfunction occurs below 140°F (60°C) or above 260°F (127°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.
- 11. Check the engine coolant level. Add if low and retest.
- 22. Inspect the wiring and connectors to the coolant temperature sensor for damage or corrosion.
- 33. Using a multimeter, check the resistance of the coolant temperature sensor at operating temperature. Compare values against specifications.
- 44. If the sensor reading remains out of range, replace the coolant temperature sensor and retest.
Common causes
- Faulty engine coolant temperature sensor
- Electrical short or open circuit in the sensor wiring
- Corroded connectors on the sensor
- Low coolant level affecting sensor readings
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; you can drive but should fix it soon to avoid engine performance issues.
Will this code come back after I clear it?
It may return if the underlying issue isn't fixed, especially if the sensor is faulty.
Why do I keep seeing this code with SPN 100?
SPN 100 often indicates an issue related to coolant temperature as well, suggesting a common problem with temperature readings.
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