P2BB7Engine Coolant Temperature Sensor 6 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
- With P2BB7 the sixth coolant sensor delivers an electrically valid value that nevertheless makes no sense. Plausibility tests of this kind compare the sensor with the other engine temperatures after a long cold soak, expect a clear rise once the engine warms up, and flag a value that never moves. CARB requires such rationality monitoring for coolant temperature inputs on which emission functions depend. No manufacturer publishes a set condition for P2BB7; GM, whose 2019 and 2025 engine tables do read a sixth coolant input, lists only the electrical codes P2BB8, P2BB9 and P2BBA for it. Possible reasons are a drifting element, a sensor sitting in a branch without flow because a pump or valve has failed, or contact resistance. Pure circuit faults are P2BB6, P2BB8 and P2BB9.
- What you may notice
- MIL on, usually only after a cold start and warm-up
- Sensor 6 value lags or stays flat compared with the other coolant sensors
- Likely causes
- PossibleSensor 6 element drifted out of its characteristic curve
- PossibleNo coolant flow at sensor 6 due to failed pump, valve or air pocket
- RareContact resistance at connector or terminals
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €40 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.