Turbocharged gasoline engines on some 2000-2019 GM models may experience poor performance in very cold ambient temperatures (32 °F, 0 °C or lower). (Fig. 19) DTCs P0299 (Engine Underboost) or P2227 (Barometric Pressure Sensor Performance) may set. In cold temperatures, ambient and PCV moisture can freeze in the charge air cooler, which would restrict flow and cause DTCs P0299 and/or P2227.
Fig. 19
DTC P0299 may set when the ECM detects that the actual boost pressure is less than the desired boost pressure by a calibrated amount for greater than three seconds. When DTC P0299 is set, the ECM will disable boost control and limit the system to mechanical boost only, resulting in a substantial decrease in engine power.
DTC P2227 may set if the actual value of the Barometric Pressure Sensor (BARO) is not within a predetermined range of the calculated BARO.
If these conditions are found, inspect the air induction system, including the charge air cooler, for signs of ice restricting the air flow or covering any related pressure sensors. These inspections should be performed prior to following the diagnostic steps for any set DTCs or performing any service as recommended in other bulletins or PI’s.
Allow any ice to melt so that the moisture can be drained from the induction system, including the charge air cooler, without component damage. Once any excessive moisture has been removed, retest the engine performance and follow the normal diagnostic steps for any symptoms found.
– Thanks to Rob Halas
