Engine Coolant Temperature Sensor 1 Out of Range - High
Engine coolant temperature is too high according to the sensor.
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)
The engine coolant temperature sensor is reporting a temperature that's higher than it should be, which can lead to overheating and engine damage.
What the computer is actually seeing
The ECM is detecting a signal voltage from the engine coolant temperature sensor that exceeds the normal operating range, typically over 240°F (115°C).
What a healthy reading looks like
Normal coolant temperature is between 160°F to 220°F (71°C to 104°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. If low, top it off and see if the code returns.
- 22. Inspect wiring and connector for the coolant temperature sensor for damage or corrosion. Repair as necessary.
- 33. Use a scan tool to monitor actual coolant temperature against the sensor reading. If the reading is incorrect, replace the sensor.
- 44. Check the thermostat operation. If stuck closed, replace the thermostat.
- 55. If all else checks out, consider engine overheating issues (radiator blocked, pump failure).
Common causes
- Faulty coolant temperature sensor
- Wiring issue or poor connection in the sensor circuit
- Low coolant level leading to overheating
- Thermostat stuck closed
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
No, high coolant temperature can lead to engine damage. Repair it immediately.
Will this code come back after clearing?
Yes, if the underlying issue isn't fixed, the code will likely return.
Why does it sometimes pair with other codes?
Other codes related to engine performance or temperature may indicate cascading failures such as overheating.
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