Turbocharger/Supercharger B Underboost Condition

Turbocharger/Supercharger B Underboost Condition

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles that have a turbocharger or supercharger. Brands of vehicles affected may include but are not limited to Ford, GMC, Chevy, VW, Audi, Dodge, Hyundai, BMW, Mercedes-Benz, Ram, etc. Although generic, the specific repair steps may vary depending on make/model.

The P0299 DTC code refers to a condition where the PCM/ECM (powertrain/engine control module) has detected that the "B" turbocharger or supercharger is not providing a normal amount of boost.

Refer to a vehicle specific repair manual to determine which is the "B" turbocharger or supercharger in your particular application. That could be due to a variety of reasons, which we detail below. On a normally operating turbocharged or supercharged engine the air going into the engine is pressurized and that's part of what makes so much power for an engine of it's size. If this code is set, you will likely notice reduced power output.

In the case of Ford vehicles, this may apply: "The PCM checks for a minimum throttle intake pressure (TIP) PID reading during engine operation, which indicates an underboost condition. This DTC sets when the PCM detects that the actual throttle intake pressure is less than the desired throttle intake pressure by 4 psi or more for 5 seconds."