P2BBCTurbocharger/Supercharger Bypass Valve A Position Sensor Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2BBC sets when the position signal of the bypass valve A sensor sits too low – usually an open signal wire, a short to ground or a lost 5 V supply to the sensor. GM uses the code on the 2019 Corvette ZR1 with the supercharged LT5, whose electronic compressor recirculation valve (eCRV) reports its position as a share of the reference voltage: a raw value under 10 % in 10 of 14 samples taken every 100 ms counts as a failure, checked while relay voltage is at least 11 V and the engine is not cranking. It is a Type A fault, so the MIL comes on in the first trip. The opposite case, a signal stuck near the reference, is P2BBD; a valve that does not follow its command is P23AA. Unable to trust the valve position, the module typically limits boost.
- What you may notice
- Check engine light on in the first trip
- Limited boost and weaker acceleration
- Possibly further 5 V reference codes if the supply is shorted
- Likely causes
- LikelySignal wire shorted to ground or chafed against the engine
- PossibleOpen 5 V reference wire or reference shorted by another sensor on the same supply
- PossiblePushed-out or corroded terminal in the valve connector
- RareDefective position sensor in the valve actuator
- 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 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.