P0299

Turbocharger/Supercharger A Underboost Condition

Turbo / boost control Generic OBD-II High

What it means

P0299 means the engine isn't producing the boost pressure the ECM expected from the turbocharger or supercharger. The most common cause is a leak in the charge-air plumbing, but a stuck wastegate, faulty boost-control solenoid, or a restricted intake can also be to blame. Expect reduced power until it's fixed.

High

Can I keep driving? The car will run but feels sluggish and may drop into reduced-power limp mode; you can drive gently to a shop, but avoid hard acceleration until it's fixed.

Real-world scan data

Seen in

3,515

scans in the past year

Found in

0.6%

of scans

1.0%

of scans that found faults

Appears alongside · share of P0299 scans

P2263in 11.6% of scans

P0101in 9.0% of scans

P0113in 8.2% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Noticeable loss of power and slow acceleration
Hesitation or lag under load
Reduced-power limp mode on hard throttle

Common causes

Most likely first

Boost leak — split or loose charge-pipe, intercooler hose, or clamp (most common)Likely
Sticking or worn wastegate or boost-control actuatorCommon
Faulty boost-control solenoid or vacuum linesCommon
Restricted intake or exhaust, or a clogged air filterLess often
Dirty or failing MAF sensor misreporting airflowLess often
Worn turbocharger or supercharger (bearing, vanes)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame and compare commanded vs actual boost to confirm the underboost.
Pressure- or smoke-test the charge-air system for split hoses and loose clamps between the turbo and intake.
Check the wastegate/boost-control actuator and solenoid for free movement and proper vacuum, and inspect the control lines.
Inspect the air filter and intake/exhaust for restrictions; clean or test the MAF sensor.
Only condemn the turbo itself after leaks and controls are ruled out; clear and road-test.

FAQ

Quick answers

Is it safe to drive with P0299?+

Short, gentle driving is usually okay, but a stuck-open wastegate or leak means poor power and possible limp mode, so get it diagnosed soon.

Can I just clear P0299?+

It returns the next time the engine can't make its target boost. Find the leak or control fault first, then clear it.

Read & clear P0299 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX