P2B90Turbocharger/Supercharger B Temperature Sensor Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2B90 means the signal of temperature sensor B has dropped below the lowest value the engine computer accepts. What that says about temperature depends on the element: an NTC thermistor loses resistance when hot, so a low signal reads as extreme heat, whereas a platinum resistor of the kind Heraeus patented for turbo protection (US8328419B2) gains resistance with heat, so a low signal reads as extreme cold. Electrically both point the same way: a signal wire touching ground or a shorted element. No manufacturer publishes this code, so the sensor type of a given engine must be taken from its service data. CARB 13 CCR 1968.2 (e)(15) keeps low and high faults apart. The high counterpart is P2B91, the matching code for sensor A is P2B6F.
- What you may notice
- Warning lamp with stored code
- Sensor B shows a fixed extreme value even on a cold engine
- Likely causes
- LikelySignal wire shorted to ground, for example melted insulation
- PossibleSensor element shorted internally
- RareFaulty input stage in the engine computer
- 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: €60 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.