Turbocharger/Supercharger Underboost Condition
The boost monitor detected less pressure than requested during its evaluation. Charge-air leakage, restricted flow, boost control or inaccurate measurement can create this difference, as can turbocharger damage. The code does not prove that the turbocharger itself has failed. Avoid hard acceleration and ask the shop to compare requested and measured boost and investigate the pressure-control system.
Can I keep driving?
A code alone cannot establish that driving is safe. With a flashing warning, shaking, overheating, unusual mechanical noise, smoke or substantial power loss, stop safely and arrange assistance. Otherwise ask a repair shop for vehicle-specific advice before driving further.
Flashing light, burning smell or smoke? Pull over safely. Danger to life: call 911.
What does this code mean for your car?
The same code can need different checks depending on the model and engine. Enter your vehicle details to find relevant sources and checks.
Symptoms
- Significant loss of power
- Limp mode
- Whistling or whooshing under acceleration
- Exhaust smoke (in some cases)
Possible causes
- 1Cracked or loose boost/intercooler hose
- 2Wastegate or turbo actuator fault
- 3Faulty boost pressure sensor
- 4Worn turbocharger
These possibilities are not ranked by frequency and do not diagnose your vehicle.
Checks you can safely do yourself
Safe checks only: engine off and cold, car on level ground.
- Inspect boost hoses and clamps (engine cold) - oil around a joint suggests a leak
When you need a shop
Request comparison of commanded and measured boost, intake pipe inspection and turbo control tests using manufacturer procedures. Smoke, unusual noise or power loss that makes traffic unsafe calls for a safe stop and assistance.
How much does it cost?
A US repair estimate needs a diagnosis and a local shop quote.
No verified US repair estimate is available. Ask a local shop to diagnose the vehicle before quoting parts and labor.
Get 2-3 quotes
Investigate this code for my carFAQ
Can I keep driving with P0299?
A code alone cannot establish that driving is safe. With a flashing warning, shaking, overheating, unusual mechanical noise, smoke or substantial power loss, stop safely and arrange assistance. Otherwise ask a repair shop for vehicle-specific advice before driving further.
What can cause P0299?
Possibilities to investigate include Cracked or loose boost/intercooler hose; Wastegate or turbo actuator fault. The code does not prove a particular part has failed; diagnose before replacing parts.
If I clear the code, is it fixed?
No. Clearing a code does not repair its cause and may erase diagnostic evidence or reset readiness monitors. It may return when the monitor runs again. An unlit warning does not prove the vehicle is fault-free.
I saw this code on a car I'm thinking of buying - now what?
Don't run, don't shrug it off. Ask the seller for a shop diagnosis before you sign, and use what it finds to negotiate.
How much does fixing P0299 cost?
We do not have a verified US repair quote for your vehicle. Diagnosis, local labor rates and the confirmed repair determine the price. Get 2-3 quotes.