The shifts are electronically controlled. The main sensor is the throttle position sensor. It sends a signal to the ECM of the throttle position and the shift solenoids are turn on and off based on road speed as well.
I attached a flow chart for shifting issues for you to view.
Are there any codes in the system?
How long since you changed the fluid and filter?
Images (Click to enlarge)
Sunday, May 17th, 2020 AT 3:13 AM