P23AATurbocharger/Supercharger Bypass Valve A Stuck
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P23AA concerns bypass valve A of a turbocharger or supercharger, which opens a path around the compressor to relieve boost when the throttle closes or at part load. The code means the valve no longer follows its command and sits fixed. GM applies P23AA to the electronically positioned supercharger bypass valve of the 2019 Corvette LT5: if the measured position deviates from the target by more than 25 % for at least 1 s while the valve is barely moving (under ±10 % per second), 10 failures in 14 samples at 6.25 ms set a Type A fault with the MIL in the first trip. The circuit codes P0033 to P0035 and the mechanical test P2261 cover other faults of the valve. Stuck open it costs boost and power; stuck closed it can cause compressor surge and noise on lift-off.
- What you may notice
- Reduced boost and power
- Fluttering or surging noise when lifting off
- MIL on, possibly limited power mode
- Likely causes
- LikelyValve or actuator mechanically seized (deposits, wear)
- PossibleFaulty electric actuator or position sensor of the valve
- PossibleDamaged linkage or valve plate
- RareHigh resistance in wiring or connector
- 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: €150 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.