Engine Coolant Temperature Sensor Out of Range
The engine coolant temperature sensor is reporting an out-of-range value.
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What it means (plain English)
The engine coolant temperature sensor measures how hot the coolant is, which should be around 190-220°F in normal operation. If it's too low or too high, like below 50°F or above 250°F, it triggers this code because the readings aren't making sense for engine operation.
What the computer is actually seeing
The ECM sees a value from the coolant temperature sensor that is outside the expected range, indicating a potential issue with the sensor itself or the coolant.
What a healthy reading looks like
Normal coolant temperature should be between 190°F and 220°F. Reports below 50°F or above 250°F are out of range.
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 coolant level—ensure it's between the minimum and maximum marks.
- 2Inspect wiring and connector of the coolant temperature sensor for signs of wear, corrosion, or damage.
- 3Use a scan tool to read the live data from the coolant temperature sensor and compare it to actual coolant temperatures (use an infrared thermometer as a reference).
- 4If the readings are out of range, replace the coolant temperature sensor. If not, check for issues with the wiring or grounds, and retest.
Common causes
- Failed coolant temperature sensor
- Shorted or corroded wiring
- Coolant level too low
- Faulty engine control module (ECM)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It may be safe to drive, but monitor engine temperature closely until repaired.
Will this code come back after repair?
If the repair is done correctly and the wiring/sensor are good, it shouldn't come back.
Why do I see this code frequently with overheating issues?
Overheating can cause readings to spike, triggering the code if the sensor fails or reacts improperly.
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