P0299: Turbo/Supercharger Underboost Condition
83 vehicles · 27 makes · $50-$15,000 repair
Most Reported On
P0299 is an OBD-II diagnostic trouble code meaning “Turbo/Supercharger Underboost Condition.” P0299 means the engine computer detected an underboost condition — the turbocharger or supercharger is producing less boost pressure than the PCM expects for the given conditions. The computer compares the manifold/boost pressure sensor reading to a target based on engine load, and when actual boost falls short, it sets this code. The most common real-world cause is a leak somewhere in the intake/charge-air path. You'll typically feel reduced power or sluggish acceleration, and the engine may go into a reduced-power mode. This code is most commonly reported on 2022-2023 Toyota Tundra (1794 Edition, Capstone, Limited, Platinum, SR, SR5, TRD Pro, i-FORCE MAX), 2004-2012 Volvo S40, and 2007-2013 MINI Cooper S (John Cooper Works, S), plus 80 other vehicles, with repair costs ranging from $50 to $15,000.
Common Causes
Typical Repair Cost
Based on 103 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P0299, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (83)
S55 Plastic Charge Pipe Cracking
Plastic Charge Pipe Blow-Off Under Boost
Plastic Charge Pipe Failure Under Boost
Turbo Wastegate Rattle at Idle
S58 Plastic Charge Pipe Cracking Under Boost
S58 Plastic Charge Pipe Cracking Under Boost
S63 V8 Twin-Turbocharger Failure - F10 M5
S63 Twin Turbo Wastegate Rattle - E70/F85 X5 M
N63 Turbo Wastegate Rattle (xDrive50i)
N54 Twin Turbo Wastegate Rattle - E89 Z4 sDrive35i/35is
Charge Pipe Cracking Under High Boost (S58 Engine)
Turbocharger Wastegate Rattle (N55, N20, B58 Engines)
1.4L Turbo PCV Valve Cover Diaphragm Failure
1.5T Turbo PCV Valve and Oil Leak Issues
2.0L Turbo (LTG) Engine Problems
Turbocharger Oil Leak and Failure
1.5T LFV/LYX Engine PCV System and Oil Consumption
1.4L Turbo Wastegate Actuator Failure
1.5L Turbo Charge Air Cooler (Intercooler) Condensation Restricting Airflow — Underboost / Reduced Engine Power
1.4T Ecotec Turbo and Coolant Issues
2.7L Turbomax (L3B) Cold-Start Rattle and Wastegate Actuator Wear
Turbo Oil Feed Line Leak (1.4T LUJ/LUV)
1.5L turbo coolant loss / overheating (head gasket & intercooler condensation)
Turbo Wastegate Regulator Solenoid Failure Causing Overboost/Underboost and Reduced Engine Power
6.7L Power Stroke Early-Generation Turbocharger Failure (2011-2014)
3.5L EcoBoost Twin Turbocharger Failure
2.0L EcoBoost Cold-Start Hesitation and Bucking at Low Speeds
6.7L Power Stroke Turbocharger Bearing and Actuator Failure
Turbocharger Boost Pressure Sensor / MAP Sensor Failure (2.0L EcoBlue)
EcoBoost Turbocharger Wastegate Actuator Rattle
Super Coupe Supercharger and Intercooler Failure
7.3L Powerstroke Turbo Pedestal O-Ring Leak
3.5L EcoBoost Intercooler Condensation Causing Shudder and Limp Mode
2.3L EcoBoost Turbo Wastegate Rattle and P0299 Underboost / Limp Mode
Turbo Wastegate Actuator Sticking Causing Limp Mode
EcoBoost Turbo Underboost (P0299) — Boost Leaks, Bypass Valve Diaphragm, and Warped Air Deflector
3.5L EcoBoost Turbocharger Wastegate Failure — Stuck Wastegate / Reduced Engine Power
Turbo Wastegate Rattle on Cold Start
2.3L Turbo VVT Actuator and Turbocharger Failure
K04 Turbocharger Failure and Boost Leaks
Turbocharger Oil Feed Line Leak and Turbo Failure
Turbocharger Seal Failure and Oil Burning
Turbocharger Oil Starvation and Failure
Turbo Baja (EJ255) Turbocharger Failure and Banjo Bolt Screen Restriction
Turbo Boost Leak and Wastegate Rattle
Turbo Failure From Clogged Oil-Supply Banjo Bolt Filter (Forester XT, EJ255)
Turbocharger Failure/Wastegate Rattle
2.0T Turbocharger Wastegate Rattle and Failure
Early MK7 IHI Turbocharger Failure
Turbo Diverter Valve (DV) Failure and Boost Leak
Diverter Valve (DV) Failure
G60 Supercharger Failure
IS38 Turbocharger Wastegate Rattle and Electronic Actuator Failure
IS20 Turbocharger Failure
1.9 TDI VNT turbo actuator sticking and MAF sensor failure (power loss / limp mode)
PCV System Failure Causing Oil Leaks and Engine Damage
T5/T6 Engine Excessive Oil Consumption
Turbocharger Failure and Wastegate Rattle
Electronic Throttle Module (ETM) Failure
T5 Turbocharger Failure from Oil Starvation
T6 3.0L Twin-Scroll Turbo Failure and Oil Leaks
T4/T5 Turbocharger Oil Feed Line Leak
T6 Twin-Charged Engine Supercharger Drive Belt and Turbo Oil Line Leak
T6 Supercharger Electromagnetic Clutch Failure
2.5L T5 PCV Oil Trap/Breather Box Failure
D4 Diesel Turbocharger Wear (European-market diesel) — Power Loss, Black Smoke and Whistling
FAQ
What does P0299 mean?
P0299 stands for "Turbo/Supercharger Underboost Condition." P0299 means the engine computer detected an underboost condition — the turbocharger or supercharger is producing less boost pressure than the PCM expects for the given conditions. The computer compares the manifold/boost pressure sensor reading to a target based on engine load, and when actual boost falls short, it sets this code. The most common real-world cause is a leak somewhere in the intake/charge-air path. You'll typically feel reduced power or sluggish acceleration, and the engine may go into a reduced-power mode.
What are the most common causes of P0299?
The most common causes of P0299 are: Boost/intake leak (cracked or loose charge-air hose or intercooler), Faulty or sticking turbo wastegate or actuator, Stuck or clogged variable-geometry turbo vanes (VGT), Faulty boost pressure or MAP sensor, Leaking or disconnected vacuum/boost control lines, Restricted air intake or clogged air filter, Failed boost control solenoid, Worn or failing turbocharger. The specific cause varies by vehicle.
How much does it cost to fix P0299?
Repair costs for P0299 range from $50 to $15,000, depending on the vehicle and root cause.
Which vehicles are affected by P0299?
Au7o has documented P0299 across 83 vehicle models from 27 manufacturers: Audi, BMW, Buick, Chevrolet, Chrysler, Citroen, Dodge, Fiat, Ford, GMC, Honda, Hyundai, Jeep, Kia, Land Rover, MINI, Mazda, Mercedes-Benz, Nissan, Peugeot, Porsche, Renault, Saab, Subaru, Toyota, Volkswagen, Volvo.
Sources (12)
- mediaCarPro: Toyota Expands Twin-Turbo V6 Engine Recall
- mediaThe Drive: We Finally Know Why the Toyota Tundra V6 Keeps Self-Destructing
- mediaAutoGuide: Toyotas Twin-Turbo Tundra Trouble Just Got Bigger
- article6.7L Turbo Failure - PowerStrokeHelp.com
- article2011-2014 Post-Warranty Power Stroke Fix: Ditching the VGT - DrivingLine
- videoFord Transit 3.5L EcoBoost Turbocharger Replacement - EricTheCarGuy
- mediaClassAction.org: Honda Hid Engine Oil Dilution Defect in CR-V, Civic, Accord
- mediaMyCarVoice: Honda 1.5L Turbo Oil Dilution Problems Lawsuit (MY2018-2021)
- mediaTop Class Actions: Honda Oil Dilution Class Action Settlement
- otherCarComplaints: Honda Fuel Dilution Problems Cause Class-Action Lawsuit
- videoEricTheCarGuy - Diagnosing and Fixing Turbo Wastegate Rattle on VW Jetta
- ForumReddit r/MechanicAdvice: 2023 Mazda CX-50 Turbo Wastegate Rattle on Cold Start
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.