OBD-II code · Powertrain (generic)
P012B Turbocharger/Supercharger Inlet Pressure Sensor A Circuit Range/Performance
Turbo inlet pressure sensor A reading implausible. 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 P012B?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor reading drifted
- Less likelySensor element aged beyond calibration window
- Less likelySensor mounting loose - signal damping
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
- Turbo Inlet Pressure Sensor A
Related codes
- P0128Coolant Thermostat Below Regulating Temperature
- P0129Barometric Pressure Too Low
- P012ATurbocharger/Supercharger Inlet Pressure Sensor A Circuit
- P012CTurbocharger/Supercharger Inlet Pressure Sensor A Circuit Low
- P012DTurbocharger/Supercharger Inlet Pressure Sensor A Circuit High
- P012ETurbocharger/Supercharger Inlet Pressure Sensor A Circuit Intermittent/Erratic
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.