Coolant Temperature Sensor 1 Out of Range
Coolant temperature reading is outside of expected parameters.
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What it means (plain English)
The engine's coolant temperature sensor is reporting a temperature that is too high or too low, which can lead to overheating or poor performance.
What the computer is actually seeing
The engine control module (ECM) reads coolant temperature and expects values between 180°F and 220°F (82°C to 104°C). If it sees a value lower than 160°F (71°C) or higher than 250°F (121°C), the code triggers.
What a healthy reading looks like
Coolant temperature should ideally be between 180°F and 220°F (82°C - 104°C) during normal operation.
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; it should be above the minimum mark.
- 2Inspect the coolant temperature sensor wiring for damage or disconnection; repair as needed.
- 3Test the coolant temperature sensor with a multimeter; should show resistance within expected range (typically 10k ohms at 77°F (25°C)).
- 4Check the temperature reading using a scan tool; if outside expected values, replace the sensor and retest.
Common causes
- Faulty coolant temperature sensor
- Open or shorted wiring in the sensor circuit
- Coolant level too low affecting sensor reading
- Thermostat stuck open or closed
- Corroded or poor electrical connections at the sensor
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It depends on the temperature readings. If the sensor is reading extreme values, it could lead to engine damage.
Will this code return after clearing?
If the underlying issue isn’t fixed (like a faulty sensor or bad wiring), it will likely come back.
Why does this code sometimes pair with SPN 4110?
Both codes relate to coolant temperature readings; if one sensor fails, the other may also be affected.
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