Code Definition

P0299 — Turbocharger/Supercharger Underboost

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0299

P0299 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0299 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The Engine Control Module (ECM) monitors intake manifold pressure or the charge air pressure sensor to confirm the turbocharger or supercharger is producing the commanded boost pressure for the current engine load and speed. DTC P0299 is set when actual boost remains measurably below the target boost map value for a calibrated time during a boost demand, indicating the forced induction system is underperforming. Common causes include boost leaks in the charge air system, a wastegate or variable geometry turbo (VGT) stuck open, a failed boost control solenoid, worn or damaged turbo internals, o...

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