Engine Coolant Temperature Sensor Circuit High
The engine coolant temperature sensor signal is too high.
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 computer is reading a coolant temperature that's higher than normal, meaning the sensor is likely faulty or sending incorrect signals.
What the computer is actually seeing
The ECM sees a coolant temperature signal above its designed max limit, typically around 240°F (115°C) or higher, indicating a potential overheating issue or sensor failure.
What a healthy reading looks like
Normal coolant temperature should be between 180°F and 220°F (82°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 for obvious wiring issues or corrosion at the sensor connector and wiring harness. Repair if necessary. Decision: If repaired, clear code and retest; if not, proceed to step 2.
- 22. Test the coolant temperature sensor with a multimeter. At engine temperature around 200°F (93°C), you should see approximately 2.5 to 3.0 volts output. Decision: If voltage is in range, check for other issues; if above threshold, replace the sensor.
- 33. Inspect engine for overheating signs (coolant leak, failed thermostat, etc.). Decision: If overheating, resolve underlying issue; if no signs, further diagnostics may be needed.
Common causes
- Faulty coolant temperature sensor
- Wiring issues or corrosion in the connector
- Overheating engine conditions due to other failures
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not safe to drive as it may indicate overheating, which can cause engine damage.
Will this code come back after clearing it?
If the underlying issue isn’t resolved, the code will likely return.
Why is this code paired with overheating symptoms?
It signals the ECM that the coolant temperature is excessively high, potentially indicating actual overheating.
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 →