What it means
Engine coolant temperature sensor 3 is not performing within its expected range. The code does not specify the sensor's location or function; these depend on the vehicle.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Coolant temperature sensor 3 provides a temperature signal that a control module checks for plausible behavior. This code sets when the signal is electrically present but its range or response does not match expected operation; sensor 3's location and function depend on the vehicle.
Common causes
Most likely first.
- Sensor reading drifted
- Sensor element aged beyond calibration window
- Sensor mounting loose - signal damping
Symptoms
- Check engine light on
- Cooling fan runs constantly or not at all
- Cabin heater weak or excessively hot
- Possible long warm-up time or hard cold start
How to diagnose it
- Record freeze-frame data and compare sensor 3's reading from a cold start through warm-up with other temperature readings and the actual engine temperature.
- Identify sensor 3 from vehicle service information and check that it is firmly mounted in its specified position.
- Inspect its connector and wiring for looseness, corrosion, or damage that could distort the reading.
- Monitor sensor 3 live data during warm-up to look for a reading that lags, drifts, or disagrees with other temperature information.
- Test the sensor's response and circuit against the manufacturer's specification; replace the sensor only if its reading remains out of range with sound wiring.
Common fixes
- Secure sensor 3 correctly if it is loose or improperly seated.
- Clean or repair a poor sensor 3 connector contact.
- Repair wiring that interferes with the sensor signal.
- Replace coolant temperature sensor 3 if its response fails the manufacturer's specification.
Can I keep driving?
Drive cautiously while watching the temperature gauge, since an implausible sensor 3 reading can affect fan operation or warm-up control. Stop if the engine overheats or the cooling fan does not respond as needed.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.