OBD-II code · Powertrain (generic)
P0239 Turbocharger/Supercharger Boost Sensor B Circuit
Generic electrical fault on boost pressure sensor B (twin-turbo or two-stage system). Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
Is it safe to drive with P0239?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor failed
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
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Boost Pressure Sensor B, Sensor Wiring
Related codes
- P25F2Turbocharger/Supercharger Boost Sensor C Circuit
- P0236Turbocharger/Supercharger Boost Sensor "A" Circuit Range/Performance
- P0237Turbocharger/Supercharger Boost Sensor "A" Circuit Low
- P0238Turbocharger/Supercharger Boost Sensor "A" Circuit High
- P023ACharge Air Cooler Coolant Pump A Control Circuit/Open
- P023BCharge Air Cooler Coolant Pump A Control Circuit Low
- P023CCharge Air Cooler Coolant Pump A Control Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.