Coolant Temperature Sensor 2
Coolant Temperature Sensor 2 reading is out of expected range.
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What it means (plain English)
This code means the second coolant temperature sensor is giving a reading that's way too high or too low compared to what the engine's expecting.
What the computer is actually seeing
The engine control module (ECM) reads the second coolant temperature sensor and expects a normal range anywhere from 180°F to 220°F (82°C to 104°C). If the reading goes outside this range, it triggers a fault code.
What a healthy reading looks like
Normal coolant temperature readings should be between 180°F to 220°F (82°C to 104°C); readings below 160°F or above 230°F trigger the code.
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.
- 1Check wiring harness and connectors for any visible damage or corrosion. Repair if necessary.
- 2Verify coolant level; ensure it’s at the proper mark. Refill if low to rule out false readings.
- 3Using a scan tool, monitor the coolant temperature readings. They should be within 180°F to 220°F (82°C to 104°C). If not, proceed to the next step.
- 4Disconnect the coolant temperature sensor and measure its resistance. Compare against specifications in service manual for temperature vs. resistance.
- 5If out of spec, replace the coolant temperature sensor. If the sensor checks out, investigate the ECM for correct operation or wiring harness issues.
Common causes
- Faulty coolant temperature sensor
- Wiring issues or bad connectors
- Coolant leaks affecting temperature
- Incorrect coolant levels
Typical repair cost
$$
Related codes
Frequently asked questions
Can I still drive the vehicle with this code?
Yes, but you should fix it soon to prevent overheating or further engine damage.
Will this code come back after I clear it?
If the underlying issue isn’t fixed, it will likely return.
Why does this code appear with SPN 652?
SPN 652 relates to the primary coolant temperature sensor, indicating that both sensors could be experiencing similar issues or a common wiring problem.
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