Engine Coolant Temperature Too High
The engine coolant temperature is exceeding normal operating limits.
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 getting too hot, usually over 220°F (104°C), indicating a problem with cooling.
What the computer is actually seeing
The engine control module (ECM) sees coolant temperature readings above the set threshold of 220°F (104°C).
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 coolant level in the reservoir and radiator. Is it low? If yes, top off and recheck for leaks.
- 22. Inspect for visible leaks or damage to hoses, radiator, and connections. Any leaks found? Fix those issues first.
- 33. Test the coolant temperature sensor for proper resistance at given temperatures. Is the reading within expected range? If not, replace sensor.
- 44. Remove and inspect the thermostat. Is it stuck closed? Replace if necessary.
- 55. Check the operation of the water pump. Is it functioning (no leaking, noise, or lack of circulation)? If not, replace the pump.
Common causes
- Low coolant level in the reservoir or radiator
- Faulty thermostat stuck closed
- Blocked radiator or coolant passages
- Inoperative water pump
- Bad coolant temperature sensor
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
No, driving with high engine temperatures can cause severe engine damage.
Will the code come back after repairs?
If the root cause is fixed correctly, the code should not return.
Why does this code appear alongside SPN 111?
SPN 111 is often related to coolant temps, so if one is triggered, the other commonly follows.
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