Drive Range, Fourth Gear: Notes
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
As the vehicle speed increases, the transmission control module (TCM) receives input signals from the automatic transmission input and output speed sensors, the throttle position sensor and other vehicle sensors to determine the precise moment to command OFF the normally-low 1-3- 5-6-7 control solenoid. At the same time the normally-high 4-5-6-7-8 reverse control solenoid is commanded ON to regulate 4-5-6-7-8 reverse clutch apply.