P0235: Turbocharger/Supercharger Boost Sensor A Circuit
What to do
Expect noticeably reduced power. Not usually damaging, but performance will stay poor until repaired.
What this code means
A circuit fault in the primary boost pressure sensor. Without a trustworthy boost reading the module cannot close the loop on boost control, so it defaults to a conservative wastegate position and limits power. On many engines this sensor is the same physical part as the manifold absolute pressure sensor, so check whether P01xx MAP codes are also stored — they may describe one component.
Likely causes
Start here
- Faulty boost pressure sensor · moderate
- Corroded or loose connector · easy
- Open circuit in sensor wiring · moderate
Less common
- Boost leak in charge pipework · moderate
Rare
- Failed control module · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P0235.