Engine Temperature Signal - Too High
Engine temperature reading is above normal operating range.
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What it means (plain English)
The engine computer thinks the engine temperature is too high, which can cause overheating and damage if it isn't addressed.
What the computer is actually seeing
The engine control module (ECM) monitors the engine coolant temperature (ECT) sensor input, which normally should range from about 190°F to 220°F (88°C to 104°C) during operation.
What a healthy reading looks like
Engine coolant temperature should normally be between 190°F and 220°F (88°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 engine coolant level. Ensure it is at the proper level. If low, top off and investigate for leaks.
- 22. Inspect the engine coolant temperature sensor wiring and connector. Look for damaged wires or corrosion. Repair as needed.
- 33. Use a scan tool to check the actual engine coolant temperature reading. Compare it with the value displayed on the dashboard gauge. If they differ significantly, proceed to the next step.
- 44. Disconnect the coolant temperature sensor and measure resistance with a multimeter. At 200°F, you should see about 1.3kΩ. If the readings are out of range, replace the sensor.
- 55. Check the thermostat operation. With the engine at operating temperature, feel the upper radiator hose. It should be hot if the thermostat is open. If not, replace the thermostat.
Common causes
- Faulty engine coolant temperature sensor
- Coolant leaks leading to low fluid levels
- Blocked radiator or cooling system
- Faulty thermostat stuck closed
- Wiring issues or connector corrosion
Typical repair cost
$$-$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not safe. Continuously high engine temperature can lead to engine damage. Get it diagnosed and repaired immediately.
Will this code come back after repair?
If the underlying issues are fixed properly, the code should not return.
Why does this code often show with SPN 105?
SPN 105 is related to the engine coolant temperature sensor. If it fails, it can incorrectly signal high temperature.
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