Engine Coolant Temperature Too High
The engine's 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 computer is detecting that the coolant temperature is over 230°F (110°C). This can lead to engine overheating.
What the computer is actually seeing
The engine control module (ECM) monitors the coolant temperature via a sensor, expecting a signal that should generally range between 160°F (71°C) and 220°F (104°C) during normal operation.
What a healthy reading looks like
Normal coolant temp should be between 160°F (71°C) and 220°F (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 the coolant level in the reservoir - ensure it's within the recommended range.
- 22. Inspect for any visible coolant leaks around hoses and connections; repair if found.
- 33. Test the coolant temperature sensor with a multimeter to ensure it's providing the correct resistance value at different temperatures.
- 44. Verify thermostat operation - if the engine heats quickly but the upper radiator hose remains cool, the thermostat may be stuck closed.
- 55. Check the operation of the water pump; listen for unusual noises or check for coolant flow in the radiator.
- 66. If all else checks out, clear the fault code and take the vehicle for a test drive to see if the code returns.
Common causes
- Low coolant level
- Cooling system leaks
- Faulty coolant temperature sensor
- Thermostat stuck closed
- Water pump failure
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
No, driving with a high coolant temperature can lead to severe engine damage and overheating.
What happens if the code comes back after clearing it?
If the code returns, further diagnosis is needed, as it indicates a persistent issue likely with the cooling system.
Can this code pair with other codes?
Yes, it can often accompany codes related to coolant flow and temperature, like SPN 1008 for high temperature.
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 →