P0299 — Turbocharger/Supercharger "A" Underboost Condition
Category: Powertrain Severity: Medium
Updated:
DTC code P0299 means: Turbocharger/Supercharger "A" Underboost Condition. It falls under the "Powertrain" category, with an estimated severity of Medium. Common causes include split or loose intercooler hose, intake manifold leak and wastegate stuck open or sticking VGT vanes; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Split or loose intercooler hose
- Intake manifold leak
- Wastegate stuck open or sticking VGT vanes
- Worn turbocharger
- Failed boost control solenoid
Symptoms
- Noticeable lack of power
- Limp mode
- Whistling or hissing on acceleration
- Black smoke (diesel)
How to diagnose it step by step
- Inspect intercooler hoses (cracks, oil, clamps).
- Smoke- or pressure-test the intake tract.
- Check the turbo actuator and solenoid.
- Check turbo shaft play.
- Clear the code and road test.
How to fix it
About 70% of the time it's a boost leak: check intercooler hoses and clamps under load. If there are no leaks, check the boost control solenoid and turbo actuator.
Estimated repair cost
Intercooler hose: $40–200. Solenoid: $40–150. New or rebuilt turbo: $700–2,000.
Frequently asked questions
What does DTC code P0299 mean?
Turbocharger/Supercharger "A" Underboost Condition.
Is code P0299 serious?
Severity Medium. Not urgent, but worth diagnosing to avoid bigger damage.
Can I keep driving with code P0299?
You can drive with reduced power, but fix the leak soon to avoid overworking the turbo.
Related codes
P0234 P0230 P0223 P0222 P0221 P0220 P0219 P0217 P0200
Refine by car make
🛒 Buy fuel injector at Autodoc (affiliate link)