Turbocharger/Supercharger A Overboost Condition
What it means
The engine computer has detected that the boost pressure produced by the turbocharger or supercharger has gone above the allowed limit. Excess boost can harm the engine, so the computer usually cuts power and enters limp mode until the fault clears.
Symptoms4
- Check engine light on with limp mode.
- A sudden strong surge under acceleration followed by a power cut.
- Unusual whistling or rushing air sound from the turbo area.
- Possible engine knock under load on gasoline engines.
Possible causes6
- Wastegate stuck closed or a seized wastegate arm.
- Cracked or disconnected hose between the turbo and the actuator or control solenoid.
- Faulty boost control solenoid.
- Sticking vanes in a variable geometry turbo on diesel engines due to carbon.
- Incorrect reading from the boost pressure sensor.
- Engine tuning that raises boost above the manufacturer limits.
How to diagnose6
- Compare desired and actual boost pressure on a scan tool during a road test.
- Inspect the control hoses between the turbo, actuator and solenoid for cracks or disconnection.
- Check that the wastegate arm or variable vane mechanism moves freely.
- Command the control solenoid with a scan tool and confirm it responds and changes the actuator pressure.
- Compare the boost sensor reading with barometric pressure with the engine off, and with an external gauge while driving.
- Check for modified engine software.
How to fix6
- Replace the cracked hose or reconnect the disconnected one.
- Replace the boost control solenoid if it is proven faulty.
- Free up or adjust the wastegate arm, and replace the actuator if it is damaged.
- Clean the variable vane mechanism, or replace the turbocharger if it cannot be repaired.
- Replace the boost pressure sensor if its reading is proven wrong, and restore the original software if it was modified.
- Clear the codes, then test under load and confirm actual boost follows desired boost.
Repair cost
In Saudi riyals; the highlighted part is the expected range for this fault.
The cost is low for a hose or solenoid, rises for an actuator, and reaches the upper end if the turbocharger must be replaced.
Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026
Frequently asked questions
Is overboost dangerous for the engine?
Yes. It can cause knock, higher temperatures and stress on pistons and gaskets, which is why the computer limits power and it should be repaired quickly.
Can engine tuning cause this code?
Yes. Raising boost with modified software can exceed the limit the computer monitors, which sets the code.
Can I drive with this code?
Only a short distance and gently, without full throttle, until the car is inspected.
This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.
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