Turbo and boost
P0299 — Turbocharger/Supercharger A Underboost Condition
The boost pressure is lower than the target the ECU requested. The engine feels weak, especially under load or when overtaking.
Common causes
- Leak in the intercooler, boost hose or clamp
- Wastegate stuck open or boost control valve fault
- Worn or damaged turbocharger
- Clogged air filter, restricted exhaust or catalytic converter
- Faulty boost pressure or MAF sensor
Symptoms
- Noticeable power loss under load
- Whistling or hissing sound from a boost leak
- Black or white smoke in some cases
- Check engine light
How to check
- Inspect all boost hoses, clamps and the intercooler for leaks or oil
- Run a boost leak test
- Check the wastegate movement, boost solenoid and vacuum lines
- Check air filter, exhaust restriction and the turbo shaft play
Can you keep driving?
Drivable at light load, but power will be limited. Repair soon to avoid further turbo or engine damage.
Related codes
Frequently asked questions
- What does P0299 mean?
- Boost pressure is lower than the target set by the ECU.
- What is the most common cause of P0299?
- A leak in the boost piping or intercooler hoses is very common; check these before replacing the turbo.
General reference information. It does not replace a diagnosis on your own vehicle. The same code can have different causes depending on make, model year and engine; check the manufacturer's documentation or ask a technician with a scan tool.