Engine Coolant Temperature Sensor
This code indicates an issue with the engine coolant temperature reading.
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 measures how hot the engine is running. If it doesn't send a proper signal, the engine can run too hot or too cold, which can cause serious damage.
What the computer is actually seeing
The ECU expects the coolant temperature signals to fluctuate within a range of 180°F to 220°F (82°C to 104°C).
What a healthy reading looks like
Normal operation shows 190°F (88°C) when warm; faults occur below 160°F (71°C) or above 240°F (116°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.
- 1Verify coolant level is adequate; should be between min and max marks on the reservoir.
- 2Inspect wiring and connectors to the engine coolant temperature sensor for damage or corrosion.
- 3Using a scan tool, check the live data for coolant temperature; it should match the ambient temperature during warm-up.
- 4If the reading is erratic or outside expected values, replace the coolant temperature sensor.
- 5Clear the code and retest; if code reappears, check for ECU updates or further system tests.
Common causes
- Damaged wiring or connectors to the coolant temperature sensor
- Faulty engine coolant temperature sensor
- Low coolant level affecting sensor readings
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
No, driving with incorrect coolant temperature can cause overheating and engine damage.
Will the code come back after repairs?
If the problem is correctly fixed, the code should not reappear.
Why does this code sometimes pair with low coolant levels?
Low coolant can cause the sensor to read inaccurately, triggering this fault code.
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 →