After replacing the Engine Control Module (ECM) on some 2020-2023 Encore GX and Trailblazer models equipped with the 1.3L turbo engine (RPO L3T) and 2022 XT4, XT5, XT6; 2022-2023 Blazer and Acadia models equipped with the 2.0L turbo engine (RPO LSY), DTCs P227C (Barometric Pressure (BARO) Sensor 2 Circuit Low Voltage) and P10BC (Barometric Pressure Sensors 1-2 Not Plausible) may set. A change in the Mass Air Flow (MAF) sensor design may require an ECM calibration update after ECM replacement.
The correct calibration is based on the design of the MAF sensor in the vehicle. There are different calibrations available for vehicles with a dual-sensor MAF and with a single-sensor MAF. (Fig. 8, 2.0L engine shown)
Fig. 8
Based on which MAF sensor is installed in the vehicle, reprogram the new ECM with the correct calibration. Follow all programming guidelines as instructed in the appropriate Service Information. In addition, when the ECM is replaced, the Intake System Learned Values Reset must be performed.
Refer to Bulletin #22-NA-188 for more details, including calibration information.
– Thanks to Matt Gager
