OBD-II Code P0973 is defined as a Shift Solenoid "A" Control Circuit Low
The Transmission Control Module (TCM) uses Shift Solenoids to control the hydraulic pressure in the transmission which is needed to apply the various clutch packs in the transmission that provide the different gear ratios needed to efficiently propel the vehicle down the road. When the TCM detects a pressure control solenoid is not performing as desired, it will set code P0973.