Excessive Engine Coolant Temperature
The engine coolant temperature is higher than the acceptable limit.
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 computer sees that the engine coolant is too hot, meaning the engine might be overheating.
What the computer is actually seeing
The engine control module (ECM) is monitoring the coolant temperature sensor and sees a reading above the threshold, typically around 245°F (118°C) for a diesel engine.
What a healthy reading looks like
Coolant temperature should be between 180°F (82°C) and 210°F (99°C) during normal operation.
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 coolant level in the reservoir and radiator. Is it low? (Yes: refill and retest, No: continue.)
- 22. Inspect for coolant leaks around the engine. Are there any visible leaks? (Yes: repair leaks and retest, No: continue.)
- 33. Test the operation of the thermostat. Is it opening properly at the proper temperature? (No: replace thermostat, Yes: continue.)
- 44. Measure the coolant temperature sensor output with a scan tool. Is it reading correctly compared to actual temperature? (No: replace sensor, Yes: continue.)
- 55. Check for blocked airflow through the radiator. Is air flowing freely? (No: clear blockage, Yes: continue.)
Common causes
- Low coolant level
- Faulty thermostat
- Blocked radiator
- Coolant leaks
- Faulty coolant temperature sensor
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
No, driving with excessive coolant temperature can lead to engine damage.
Will this code come back after repair?
If the underlying issue is resolved, the code shouldn't return.
Why is this code paired with other coolant-related codes?
It's common because multiple systems depend on proper coolant temperature for engine performance.
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