Excessive Engine Coolant Temperature
Engine coolant temperature is too high, indicating overheating.
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's computer sees that the coolant is hotter than normal, which means the engine might be at risk of damaging heat levels—usually above 220°F (104°C) when it shouldn't be.
What the computer is actually seeing
The Engine Control Module (ECM) is monitoring the engine coolant temperature through the temperature sensor. When the readings exceed the normal operating range significantly (like over 220°F), it triggers this fault code.
What a healthy reading looks like
Normal coolant temperature range is typically 185°F to 220°F (85°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 coolant level in the reservoir and rad; ensure it's between the upper and lower marks. Decision Point: Is the coolant low? If YES, refill and monitor for leaks. If NO, proceed.
- 22. Inspect for visible coolant leaks under the vehicle or around the engine. Decision Point: Are there leaks? If YES, repair as necessary. If NO, proceed.
- 33. Test the thermostat operation; it should open at its rated temperature usually around 190°F (88°C). Decision Point: Is the thermostat functioning? If NO, replace the thermostat. If YES, proceed.
- 44. Check the radiator for blockages or debris that could restrict airflow. Decision Point: Is there blockage? If YES, clean or replace the radiator. If NO, proceed.
- 55. Test the coolant temperature sensor with a multimeter; at 212°F (100°C), it should read approximately 20-30 ohms. Decision Point: Are sensor readings correct? If NO, replace the sensor. If YES, check other components.
Common causes
- Low coolant level
- Failed thermostat
- Coolant leak
- Clogged radiator
- Faulty water pump
- Bad coolant temperature sensor
Typical repair cost
$$-$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended as overheating can lead to serious engine damage.
Will this code come back after clearing it?
If the underlying issue isn't fixed, it will likely return.
Why does this code sometimes appear with SPN 6768?
Both relate to engine coolant temperature; they can indicate simultaneous issues with cooling.
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