Engine Coolant Temperature Sensor 2
The Engine Coolant Temperature (ECT) Sensor 2 is out of range.
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 coolant temperature sensor 2 measures how hot the engine coolant is. If it's too high or too low compared to normal, it can set this code.
What the computer is actually seeing
The ECM expects the ECT sensor signal to vary between 0.5V (approximately -40°C/-40°F) and 4.5V (approximately 150°C/302°F). If the signal goes outside this range, or holds steady at a non-normal voltage, the code is triggered.
What a healthy reading looks like
Look for ECT sensor readings of around 90-100°C (194-212°F) when the engine is warm during normal operation.
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 for any visible wiring damage or poor connections at the ECT sensor 2. If you find any issues, repair them and clear the code.
- 22. Measure the voltage at the ECT sensor 2 connector with the engine running. You should see a voltage between 0.5V and 4.5V.
- 33. If the voltage is out of range, check the sensor's resistance and compare it to manufacturer spec (usually around 2.5K ohms at 25°C/77°F). If it’s outside the spec, replace the sensor.
- 44. If the voltage is normal, check for coolant leaks or proper coolant levels. Ensure the system is filled and has no air pockets that might affect temperature readings.
- 55. If all checks are good but the code persists, consider checking the ECM for faults.
Common causes
- Faulty ECT Sensor 2
- Wiring issues or poor connections in the ECT circuit
- Coolant leaks affecting temperature
- ECM problem
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive long distances because an overheating engine could cause serious damage.
Will this code come back after I clear it?
If the underlying issue isn't fixed, yes, the code will likely return.
Why does this code pair with others like SPN 189?
Multiple codes can point to the same issue, indicating sensor problems or faults in the cooling system.
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 →