OBD-II code · Powertrain (generic)

P00B2 Radiator Coolant Temperature Sensor Circuit Range/Performance

Radiator coolant sensor reading implausible compared to engine coolant or expected behavior. The engine coolant temperature sensor feeds warm-up enrichment, fan control and closed-loop entry — a stuck-cold reading keeps the engine in open loop and rich forever.

Is it safe to drive with P00B2?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyThermostat stuck open
  • Less likelySensor element aged beyond calibration window
  • Less likelySensor mounting loose - signal damping

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–3 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Radiator Coolant Temp Sensor, Thermostat

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.