Engine Coolant Temperature
Indicates an issue with the engine coolant temperature 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 is monitoring how hot the coolant is to keep things from overheating. If the sensor is faulty, it won’t send the right temperature signal back to the engine control unit (ECU).
What the computer is actually seeing
The ECU expects to see a coolant temperature between 180°F and 220°F. If it's outside this range, or if the sensor fails, it throws a code.
What a healthy reading looks like
Coolant temperature should be between 180°F and 220°F under normal operation; sensor voltage typically ranges from 0.5V to 4.5V depending on the temperature.
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. If it's low, top it off and see if the code returns. Decision: Did the code return? (Yes/No)
- 22. Inspect the coolant temperature sensor connector for corrosion or damage. Clean or repair as necessary. Decision: Is the connector intact? (Yes/No)
- 33. Use a multimeter to check the resistance of the coolant temperature sensor. Compare readings with a reference chart to verify functionality. Decision: Is the sensor within spec? (Yes/No)
- 44. If the sensor is faulty, replace it. Clear the code and road test the vehicle. Decision: Did the code return? (Yes/No)
Common causes
- Faulty coolant temperature sensor
- Wiring issues (shorts or breaks in the harness)
- Low coolant level
Typical repair cost
$$
Related codes
Frequently asked questions
Can I still drive with this code?
It's drivable, but overheating could occur, so get it fixed soon.
Will this code come back after I fix it?
If the repair is done correctly, it shouldn't return.
Why is this code paired with SPN 10?
Both codes relate to engine temperature monitoring issues.
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