Engine Coolant Temperature Sensor 2
The Engine Coolant Temperature Sensor 2 is reporting out of range values.
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What it means (plain English)
The second coolant temperature sensor is either sending a signal that's too high or too low, which confuses the engine's computer about the actual temperature of the coolant.
What the computer is actually seeing
The engine control module (ECM) is receiving voltage readings from the sensor that do not match expected temperature values, typically fluctuating outside 75°F (24°C) to 245°F (118°C).
What a healthy reading looks like
Voltage should range from 0.5V (cold) to 4.5V (hot) corresponding to temperatures from about 14°F (-10°C) to 265°F (130°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 wiring and connectors going to the Engine Coolant Temperature Sensor 2 for damage or corrosion. Repair as necessary.
- 22. Verify that the engine coolant level is appropriate and that there are no leaks in the system. Fix leaks if found.
- 33. Use a multimeter to measure the voltage signal at the sensor connector. Expected values are between 0.5V and 4.5V. If readings are out of this range, proceed to the next step.
- 44. Disconnect the sensor and test again with a known-good sensor, measuring voltage output. If the readings stabilize within expected values, replace the original sensor. If not, further diagnose the ECM or wiring harness.
Common causes
- Faulty Engine Coolant Temperature Sensor 2
- Wiring issues such as shorts or opens in harness
- Poor connection at the sensor or ECM
- Coolant leaks affecting sensor performance
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity, meaning you can drive it, but fix it soon to avoid overheating or erratic engine behavior.
Will this code come back after reset?
If the underlying issue (like a bad sensor or wiring) isn't fixed, the code will likely return.
Why does this code show up with SPN 1101?
Both codes relate to coolant temperature, so if one sensor fails, the other often gets affected, causing multiple fault codes.
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