OBD-II code · Powertrain (generic)
P0242 Turbocharger/Supercharger Boost Sensor B Circuit High
Boost pressure sensor B signal voltage above expected range. 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 P0242?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal wire open
- Less likelyConnector pins corroded - high contact resistance
- Less likelySupply wire pinched against B+ source
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
- Parts involved
- Boost Pressure Sensor B, Sensor Wiring
Related codes
- P25F5Turbocharger/Supercharger Boost Sensor C Circuit High
- P023FFuel Pump Secondary Circuit/Open
- P0240Turbocharger/Supercharger Boost Sensor B Circuit Range/Performance
- P0241Turbocharger/Supercharger Boost Sensor B Circuit Low
- P0243Turbocharger/Supercharger Wastegate Actuator A
- P0244Turbocharger/Supercharger Wastegate Actuator A Range/Performance
- P0245Turbocharger/Supercharger Wastegate Solenoid "A" Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.