OBD-II code · Powertrain (generic)
P0238 Turbocharger/Supercharger Boost Sensor "A" Circuit High
The boost pressure A signal voltage is above the upper diagnostic threshold — short to supply voltage or defective sensor.
Is it safe to drive with P0238?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySensor circuit shorted to supply voltage
- PossibleBoost pressure sensor failed
- Less likelyConnector pins corroded - high contact resistance
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
- 0.3–2 h
- Emissions test
- Likely to fail
- Parts involved
- Boost Pressure Sensor, Boost Sensor Wiring
Related codes
- P0235Turbocharger/Supercharger Boost Sensor "A" Circuit
- P0236Turbocharger/Supercharger Boost Sensor "A" Circuit Range/Performance
- P0237Turbocharger/Supercharger Boost Sensor "A" Circuit Low
- P0239Turbocharger/Supercharger Boost Sensor B Circuit
- P023ACharge Air Cooler Coolant Pump A Control Circuit/Open
- P023BCharge Air Cooler Coolant Pump A Control Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.