Turbocharger boost
P0234
Turbocharger/Supercharger "A" Overboost Condition
The turbocharger or supercharger is making more or less pressure than the computer asked for.
Fix it soon
Can I keep driving? For a short while, gently. Have it checked in the next few days, and stop if the car feels, sounds or smells different. Low boost means little power, which is risky when overtaking. Too much boost can damage the engine. Drive gently until it's fixed.
Common causes
- A split or loose hose between the turbo and the engine
- A sticking wastegate or boost control valve
- A leaking intercooler
- A worn turbocharger
- A boost pressure sensor fault
Listed roughly from most to least likely. The same code can have different causes on different cars.
What to do
- Check the intake hoses and clamps from the turbo to the engine.
- Drive gently and stay off full throttle.
- Have the boost system pressure-tested.
General guidance. Your owner's manual wins. If a red warning light is on or the car drives differently, stop safely and get help.
Related codes
Track this automatically in Tagwell Auto
Tagwell Auto keeps your car's service dates and mileage, so when a code shows up you know what was done last. With a Bluetooth reader for the car's diagnostic port (called OBD-II), the phone app can read the code itself.