A leaking intercooler hose, clamp or the intercooler itself (very common). A sticking wastegate or wastegate actuator, or a failed boost control solenoid. A worn or damaged turbocharger. A restricted air filter or exhaust. A faulty boost pressure sensor.

Trouble codes › P0299

P0299 Turbocharger/Supercharger "A" Underboost Condition

Q: What does P0299 mean?

P0299 means the turbo or supercharger isn't making the boost the engine asked for, most often from a boost leak. The engine computer asked the turbo (or supercharger) for more boost pressure than it measured. Either boost is leaking out, the turbo isn't building it, or the boost control isn't working.

Turbo

P0299 means the turbo or supercharger isn't making the boost the engine asked for, most often from a boost leak.

The engine computer asked the turbo (or supercharger) for more boost pressure than it measured. Either boost is leaking out, the turbo isn't building it, or the boost control isn't working.

Can I keep driving? Yes, but get it fixed soon.

Drivable with reduced power, but avoid towing and hard acceleration until it's checked. A failing turbo can get worse quickly.

Common causes

A leaking intercooler hose, clamp or the intercooler itself (very common)
A sticking wastegate or wastegate actuator, or a failed boost control solenoid
A worn or damaged turbocharger
A restricted air filter or exhaust
A faulty boost pressure sensor

Symptoms

Loss of power, especially under load
A whooshing or hissing sound when accelerating
Reduced-power mode on some vehicles

Common on: Ford F-150, Ford Escape, Ford Explorer, Ford Expedition

Known problems: Ford 3.5L EcoBoost intercooler condensation misfire

What to check first

Inspect all intercooler pipes, couplers and clamps for oil, cracks or looseness; a boost leak tester (or smoke) finds leaks.
Check the wastegate actuator moves freely and its vacuum or electrical control works.
With a scan tool, compare desired and actual boost during a hard pull.
Look for service bulletins: several turbo engines (for example EcoBoost and others) have known boost-related fixes.

What does P0299 mean on your vehicle?

The likely cause depends on your engine. iRepair researches your exact year, make, model and engine (service bulletins, recalls and owner reports) and tells you what to check first. Your first 3 questions are free.

Ask iRepair about P0299

No scanner? Most auto parts stores read check-engine codes for free.

Related codes

General guidance for P0299 on most vehicles. Some makers use the same code a little differently; confirm in the service information for your vehicle, put safety first, and see a professional when in doubt.