Engine Cooling System Temperature Sensor 2
Fault in Engine Cooling System Temperature Sensor 2 signal.
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What it means (plain English)
The computer thinks the engine cooling temperature is wrong based on what the second temperature sensor is reporting, which could mean the sensor itself is bad or the connection is poor.
What the computer is actually seeing
The engine control unit (ECU) gets a voltage signal from the cooling temperature sensor. This signal should vary from about 0.5 volts (cold engine around 10°C) to around 4.5 volts (hot engine around 100°C). If the voltage stays at a constant state or goes above or below these ranges, it triggers the code.
What a healthy reading looks like
Expected voltage from sensor should vary from 0.5V at 10°C to 4.5V at 100°C; resistance should be around 2500 ohms at 20°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 connector and wiring for the engine cooling temperature sensor 2. Ensure there are no visible damages or corrosion. If damaged, repair or replace the wiring/connector. Decision point: Are there any visible issues? Yes - Repair/Replace, No - Proceed to Step 2.
- 22. Verify the engine coolant level. Ensure it is within the proper range according to the manufacturer's specifications. Decision point: Is coolant level acceptable? Yes - Proceed to Step 3, No - Add coolant and recheck for code.
- 33. Using a scan tool, monitor the voltage output of engine cooling temperature sensor 2 while the engine is running. It should vary as the engine warms up. Decision point: Is the voltage between 0.5V and 4.5V as expected? Yes - Check for ECM issues, No - Replace the engine cooling temperature sensor 2.
Common causes
- Faulty engine cooling temperature sensor 2
- Corroded or broken wiring
- Loose or damaged connector
- Coolant level too low
- Fault in engine control module (ECM)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; driving is generally okay but fix soon to avoid overheating issues.
Will this problem return after I fix it?
If the sensor or wiring was faulty and replaced properly, it shouldn't return unless another issue occurs.
Why does this code sometimes pair with SPN 210 or others?
They can indicate similar problems in the cooling system, often pointing to multiple sensor failures or wiring issues.
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