OBD-II code · Powertrain (generic, extended)
P23AA Turbocharger Bypass Valve A Stuck
The turbocharger bypass valve A (compressor bypass for surge protection or wastegate-style boost relief) is mechanically stuck. Boost control is impaired - either no relief on overspeed or no boost build-up depending on which position the valve is stuck in.
Is it safe to drive with P23AA?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyValve stuck due to debris or actuator failure
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1.5–5 h
- Emissions test
- Likely to fail
- Parts involved
- Turbo Bypass Valve A
Related codes
- P23A7Exhaust Heat Exchanger Bypass Valve B Stuck Closed
- P23A8Exhaust Heat Exchanger Bypass Valve B Position Sensor Stop Performance
- P23A9Communication Fault Forced Engine Shutdown
- P23ABNOx Sensor Processor Performance Bank 1 Sensor 3
- P23ACNOx Sensor Circuit Bank 1 Sensor 3
- P23ADNOx Sensor Circuit Range or Performance Bank 1 Sensor 3
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.