P00B2Radiator Coolant Temperature Sensor Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The radiator coolant temperature sensor is an NTC thermistor that measures coolant temperature on the radiator side, typically at the radiator outlet; the exact position depends on the manufacturer. Together with the engine coolant temperature sensor it gives a second measuring point, which the control module uses to diagnose the thermostat and coolant flow, for example on engines with an electrically heated map-controlled thermostat. P00B2 is a plausibility or range fault: the signal is electrically valid but does not fit the operating state, for example because it is stuck at one value. No manufacturer description naming this exact code was found; the exact logic is manufacturer-specific.
- What you may notice
- Check engine light on
- Thermostat and coolant flow diagnostics are suspended
- Often no noticeable symptoms
- Likely causes
- LikelySensor drifting
- PossibleAir at the sensor or low coolant level
- PossibleContact resistance at the connector
- RareEngine control module faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €60 – €150
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.