Fault-Code Library · Turbocharging
P0299: Turbocharger underboost condition
The engine did not produce the boost pressure requested by the controller.
Common symptoms
- •Low power
- •Hissing under load
- •Smoke
- •Reduced-power mode
Likely causes
- •Split charge hose or intercooler leak
- •Actuator or vacuum fault
- •Worn turbocharger
- •EGR or exhaust restriction
First checks
- •Pressure- or smoke-test the charge system
- •Log requested versus actual boost
- •Check actuator command and movement
Important
Confirm leaks and control faults before condemning the turbocharger.
A fault code identifies a detected condition, not a failed part. Confirm manufacturer-specific subcodes and live data.