Intake (induction) air leak or restriction, such as a cracked or loose boost hose (OBD-Codes.com). Failed, sticking or binding turbocharger or supercharger (both sources). Faulty boost/charge pressure sensor or MAP sensor (both sources). Faulty turbo/supercharger control solenoid or wastegate regulating valve (both sources). Exhaust leak, which robs the turbo of drive pressure (RepairPal). Wiring problem (RepairPal). Vehicle-specific causes listed by OBD-Codes.com: diverter valve or wastegate solenoid (VW), EGR fault, low oil pressure, ICP sensor or sticking variable-geometry turbo vanes/actuator (Ford diesel), low fuel pressure or sticking turbo nozzle control solenoid (Isuzu), failed turbo housing resonator (GM Duramax). Less often: brake booster pressure sensor failure or a PCM fault (RepairPal).

Repair or replace a leaking or cracked boost hose, clamp or intercooler connection. Replace a faulty boost/MAP sensor. Repair or replace the wastegate solenoid, diverter (blow-off) valve or turbo control solenoid. Repair an exhaust leak. Repair or replace the turbocharger or supercharger, after the simpler causes are ruled out.

P0299🔧 Air intake / TurboDrive with caution, fix soon

P0299: Turbo/Supercharger Underboost (Meaning, Causes, Fixes)

Q: What does P0299 mean?

P0299 means the engine computer asked the turbocharger or supercharger for more boost than it actually delivered. Boost leaks, a faulty boost or MAP sensor, a sticking wastegate or diverter valve and a worn turbo are common causes. Check the cheap things before replacing the turbo. Turbochargers (driven by exhaust gas) and superchargers (usually belt-driven) pressurize the air going into the engine, which is how a small engine makes a lot of power. The engine computer (PCM/ECM) uses sensors to compare the boost it requested with the boost it is getting. P0299 sets when actual boost stays below the requested amount, for bank "A" or a single turbo/supercharger. On Ford, OBD-Codes.com quotes the criterion as throttle intake pressure 4 psi or more below desired for 5 seconds. VW and Audi word it as "Boost Pressure Regulation: Control Range Not Reached," which means the same thing.

Q: Can I keep driving with P0299?

Drive with caution, fix soon. Sources differ slightly here: RepairPal rates P0299 moderate, while OBD-Codes.com says it can range from moderate to severe and that putting off the repair can lead to more extensive, costly damage. Expect reduced power, possibly a limp mode. Drive gently, avoid situations where you need full acceleration (merging, passing, towing), and get it diagnosed soon. If you hear new grinding, whining or screeching from the turbo, or see heavy smoke, stop driving and have it towed.

Reviewed 2026-10-21 · Based on 2 cited source(s)

What P0299 means

Turbochargers (driven by exhaust gas) and superchargers (usually belt-driven) pressurize the air going into the engine, which is how a small engine makes a lot of power. The engine computer (PCM/ECM) uses sensors to compare the boost it requested with the boost it is getting. P0299 sets when actual boost stays below the requested amount, for bank "A" or a single turbo/supercharger. On Ford, OBD-Codes.com quotes the criterion as throttle intake pressure 4 psi or more below desired for 5 seconds. VW and Audi word it as "Boost Pressure Regulation: Control Range Not Reached," which means the same thing.

Severity: can I keep driving?

Drive with caution, fix soon

Sources differ slightly here: RepairPal rates P0299 moderate, while OBD-Codes.com says it can range from moderate to severe and that putting off the repair can lead to more extensive, costly damage. Expect reduced power, possibly a limp mode. Drive gently, avoid situations where you need full acceleration (merging, passing, towing), and get it diagnosed soon. If you hear new grinding, whining or screeching from the turbo, or see heavy smoke, stop driving and have it towed.

Common symptoms

Check engine light on
Reduced engine power, possibly a limp mode (both sources)
Lack of boost from the turbo or supercharger (RepairPal)
Increased fuel consumption (RepairPal)
Unusual sounds from the engine or turbo (OBD-Codes.com)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Intake (induction) air leak or restriction, such as a cracked or loose boost hose (OBD-Codes.com)
Failed, sticking or binding turbocharger or supercharger (both sources)
Faulty boost/charge pressure sensor or MAP sensor (both sources)
Faulty turbo/supercharger control solenoid or wastegate regulating valve (both sources)
Exhaust leak, which robs the turbo of drive pressure (RepairPal)
Wiring problem (RepairPal)
Vehicle-specific causes listed by OBD-Codes.com: diverter valve or wastegate solenoid (VW), EGR fault, low oil pressure, ICP sensor or sticking variable-geometry turbo vanes/actuator (Ford diesel), low fuel pressure or sticking turbo nozzle control solenoid (Isuzu), failed turbo housing resonator (GM Duramax)
Less often: brake booster pressure sensor failure or a PCM fault (RepairPal)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Fix any other stored trouble codes first, then look up technical service bulletins (TSBs) for your year, make, model and engine. Many vehicles have a known fix for this code.
With the engine off and cool, inspect every intake and intercooler (boost) hose and clamp for cracks, splits, oil-soaked spots or loose connections.
Check the air filter and intake path for blockages.
Look and listen for exhaust leaks ahead of the turbo.
If you have a scan tool that shows live data, compare desired and actual boost (or MAP) readings during a gentle road test.

Typical fixes

Repair or replace a leaking or cracked boost hose, clamp or intercooler connection
Replace a faulty boost/MAP sensor
Repair or replace the wastegate solenoid, diverter (blow-off) valve or turbo control solenoid
Repair an exhaust leak
Repair or replace the turbocharger or supercharger, after the simpler causes are ruled out

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

Testing the wastegate, diverter valve, variable-geometry turbo actuator or boost control needs scan-tool commands or a vehicle-specific manual
The turbo itself is noisy, has shaft play or is leaking oil
Diesel trucks (Ford Powerstroke, GM Duramax) where the cause can involve fuel, oil pressure or EGR systems

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Does P0299 mean my turbo is bad?

Not necessarily. Both sources list several cheaper causes, such as boost leaks, sensors and control solenoids. OBD-Codes.com notes that on VWs a common fix is the diverter valve or wastegate solenoid. Rule those out before replacing the turbo.

Which vehicles commonly get P0299?

OBD-Codes.com reports it often on Ford EcoBoost and Powerstroke vehicles (F-150, Explorer, Edge, Escape, Super Duty), VW and Audi models (A4, Tiguan, Golf, A5, Passat, GTI, Q5) and Chevy/GMC Cruze, Sonic and Duramax diesels. Any turbocharged or supercharged vehicle can set it.

Will P0299 clear by itself?

RepairPal says codes can clear once the computer no longer detects the problem, but if it stays it should be diagnosed to avoid a more serious problem.

Sources

Last reviewed 2026-10-21. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.