Engine Coolant Temperature Sensor Out of Range
The engine coolant temperature sensor is reporting temperatures outside of the expected range.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
Your engine's coolant temp sensor should report a temperature usually between 190°F and 220°F. If it reads below 140°F or above 260°F, it triggers this code.
What the computer is actually seeing
The Engine Control Module (ECM) is receiving voltage signals from the coolant temperature sensor that are lower than 0.3V or higher than 4.5V, indicating an out-of-range condition.
What a healthy reading looks like
Coolant temperature should be around 190°F to 220°F when the engine is at operating temperature. Voltage from the sensor should be 0.5V to 4.5V within this 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.
- 11. Check the coolant level and add if needed. If low, this could cause incorrect readings.
- 22. Inspect wiring and connectors for corrosion, damage, or loose connections. Repair as necessary.
- 33. Use a multimeter to check the voltage at the coolant temperature sensor connector with the engine off. Expected voltage should be around 0.5V to 1.0V.
- 44. Start the engine and observe the voltage as it is warmed up. It should gradually increase; at 200°F, expect around 2.5V to 3.0V.
- 55. If voltage is outside expected range or reads flat (0.0V or above 4.5V), suspect a faulty coolant temperature sensor and replace it.
Common causes
- Faulty coolant temperature sensor
- Open or shorted wiring in the sensor circuit
- Corroded connector terminals
- Coolant leaks potentially affecting sensor performance
Typical repair cost
$$
Related codes
Frequently asked questions
Can I drive with this code?
It's likely drivable, but monitor for overheating or engine performance issues until fixed.
Will this come back after clearing?
If the underlying issue isn't addressed, yes, it will return.
Why might this code appear alongside SPN 1911?
Both pertain to temperature readings; if one sensor fails, the other may also register incorrect signals.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →