P0234 Code: Turbocharger Overboost — Causes & Fix
P0234 means the turbocharger or supercharger is producing more boost pressure than the ECM commands (overboost).
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $60 – $1,200
- Time to fix
- 30 minutes – 2 hours
What it means
Causes include a stuck wastegate, a failed boost control solenoid, a disconnected wastegate hose, or a boost sensor fault. P0234 is a generic OBD-II powertrain code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer petrol car or light truck regardless of make. Fix the underlying fault, then clear the code with an OBD-II scan tool — it will return if the problem isn't resolved.
Symptoms
- Check engine light on
- Sudden power then cut-out (fuel cut)
- Limp mode under acceleration
How to fix it
- 1
Inspect the wastegate and boost control
1. Check the wastegate actuator and its hose for correct operation. 2. Test the boost control solenoid and its vacuum lines.
- 2
Verify the boost sensor
1. Compare actual boost to commanded boost on a scan tool. 2. Repair the control fault, then clear the code.
Frequently asked questions
Why does my car cut power with P0234?
The ECM cuts fuel to protect the engine when boost runs away. Fix the wastegate/boost control before driving hard.
Last updated July 19, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.