P2B91Turbocharger/Supercharger B Temperature Sensor Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2B91 is stored when temperature sensor B delivers a signal above its permitted window. By far the most frequent reason is a broken current path: an unplugged or corroded connector, a cracked wire or an element that has burned open, which pulls the input up to its reference voltage. A short to the 5 V supply or to battery voltage has the same effect. For an NTC part this looks like severe cold, for a platinum resistor like severe heat; the sensor patent US8328419B2 from Heraeus explains why lead strain and heat cycling make such breaks a known weak point. No manufacturer publishes this code. Per CARB 13 CCR 1968.2 (e)(15) it is kept separate from the low fault P2B90 and the general circuit code P2B8F. Sensor A uses P2B70.
- What you may notice
- Warning lamp with stored code
- Sensor B stuck at an end value in live data
- Likely causes
- LikelySignal or ground wire open, connector unplugged or corroded
- PossibleSensor element or its lead wires broken by heat cycling
- RareSignal wire shorted to the 5 V reference or battery voltage
- 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.