P0235
Turbocharger/Supercharger Boost Sensor A Circuit
Turbo/boost control
Generic OBD-II
High
What it means
P0235 means the engine controller has seen a problem in the circuit for turbocharger/supercharger boost pressure sensor "A". That sensor tells the ECM how much boost the engine is making. Without a trustworthy signal, the ECM often limits boost and power to protect the engine. It usually comes down to the sensor itself or its wiring, not a mechanical turbo failure.
High
Can I keep driving? Usually yes, but the engine may drop into a reduced-power limp mode to protect the turbo — drive gently and fix it soon.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power or limp mode
- Turbo boost feels weak or inconsistent
- Poor fuel economy
Common causes
Most likely first
- Failed turbocharger/supercharger boost pressure sensor ALikely
- Damaged wiring or poor connection at the sensorCommon
- Loose or corroded electrical connectorCommon
- Failed engine control module (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check the boost sensor's live reading against actual boost.
- Inspect the sensor connector and wiring for corrosion, chafing, or loose pins.
- Verify the sensor has a proper reference voltage and ground, then compare its output to spec.
- Replace the boost sensor if its signal is out of range; repair wiring faults first. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0235?+
Short-term yes, but the engine may limit boost and power to be safe. It won't stop the car from starting — get the sensor circuit checked soon.
Can I just clear P0235?+
It will come back until the sensor or its wiring is repaired. Fix the circuit, then clear it.
Related codes
Often seen with P0235
Read & clear P0235 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX