18237 - Emission Recall - TCM Software Potential Emissions Noncompliance. - General Motors has decided to conduct a voluntary emissions recall involving certain 2017-2018 model year vehicles equipped with an 8-speed transmission (RPO MRC) that were service programmed with incorrect transmission control module, (TCM) software. Vehicles programmed with this software may, under certain downhill driving conditions, remain stuck in gear or shift up later than expected, after RPMs (Revolutions Per Minute) are already high. This condition can only be cleared by an ignition key cycle (turning the vehicle off and then back on again) or by shifting the vehicle into and out of Neutral. Dealers are to reprogram the TCM.
