Engine Temperature Sensor High
The engine temperature sensor is reporting a temperature that's too high.
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What it means (plain English)
Basically, the engine temperature sensor is saying the engine is running hotter than it should, often over 240°F (116°C). This can trigger warnings or shutdowns to protect the engine.
What the computer is actually seeing
The engine control module (ECM) expects the engine coolant temperature sensor (ECT) to give readings between 180°F and 220°F during normal operation. If it sees values consistently over 240°F, it triggers SPN 1022.
What a healthy reading looks like
Normal values for engine coolant temperature should range from 180°F to 220°F (82°C to 104°C). You should not consistently see values over 240°F (116°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 engine coolant level; it should be between the min and max marks on the reservoir. If it's low, top it up and recheck the code after driving.
- 22. Inspect the wiring and connectors to the engine coolant temperature sensor for damage or corrosion. Repair any found issues and retest.
- 33. Use a scan tool to monitor the actual coolant temperature while the engine runs. Compare this to the temperature gauge on the dashboard. If there's a large discrepancy, the sensor may be faulty.
- 44. If the coolant temperature readings are consistent but above 240°F (116°C), verify that the thermostat is functioning by monitoring engine temperatures and checking if the upper radiator hose gets hot. If not, the thermostat may be stuck closed.
Common causes
- Faulty engine coolant temperature sensor
- Wiring issue (short or open circuit)
- Coolant level too low
- Coolant flow issue (stuck thermostat)
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Not recommended. High engine temperatures can lead to severe engine damage.
Will this code come back?
If the underlying issue isn't fixed, the code will likely return.
Why is this code paired with low coolant?
Low coolant can cause the engine to run hotter, and the sensor will pick this up as an excessive temperature.
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