OBD-II code · Powertrain (generic)
P00B6 Radiator Coolant Temperature/Engine Coolant Temperature Correlation
Difference between radiator outlet and engine coolant temperatures is implausible — typically indicates a stuck thermostat.
Is it safe to drive with P00B6?
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 (slow warm-up)
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
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
- Thermostat, Radiator Coolant Temp Sensor, Engine Coolant Temp Sensor
Related codes
- P00B3Radiator Coolant Temperature Sensor Circuit Low
- P00B4Radiator Coolant Temperature Sensor Circuit High
- P00B5Radiator Coolant Temperature Sensor Circuit Intermittent/Erratic
- P00B7Engine Coolant Flow Low/Performance
- P00B8MAP - Mass or Volume Air Flow Correlation Bank 2
- P00B9Low Pressure Fuel System Pressure - Too Low. Low Ambient Temperature
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.