P2BBETurbocharger/Supercharger Bypass Valve A Position Exceeded Learning Limit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2BBE is not a wiring fault but a failed end-stop learn. GM's 2019 tables for the LT5 Corvette ZR1 describe how the electronic recirculation valve is taught after each engine shutdown: the module first drives it to the closed stop and stores the sensor value, then repeats this for the open stop. If the learned closed value falls outside 85–95 % of the sensor range, or the learned open value outside 10–20 %, the code sets at once (Type A, MIL in one trip). The learn only runs while no position-sensor or valve-circuit fault is active. Typical causes are carbon or oil deposits, a bent flap or shaft, a worn actuator gear or a sensor that has shifted. Since the learn needs a key-off, a repair is only confirmed after a full shutdown. Circuit faults of the same sensor are P2BBB to P2BBD.
- What you may notice
- Check engine light after the engine has been switched off and restarted
- Boost limited or erratic on lift-off
- Likely causes
- LikelyOil or carbon deposits keeping the valve from reaching its stops
- PossibleBent flap or shaft, or worn actuator gear
- PossiblePosition sensor shifted or drifted after a repair or with age
- RareNon-matching replacement valve with a different travel range
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.