Cannot move gearshift lever out of P (Park) with ignition ON and brake pedal depressed

Symptoms

["Remove the trim ring around the gearshift lever.", "Remove the console panel by opening the armrest, grasping the panel firmly, then pulling up. This will allow access to the gearshift assembly.", "Locate the white plastic cover at the front driver side of the gearshift lever. Locate the screw which attaches this cover and remove using a screwdriver. Remove the cover by tilting forward while pulling up and out of the gearshift assembly.", "Locate the silver button in the driver side front area of the gearshift assembly. Press and hold the silver button while moving the gearshift lever out of P (Park) into N (Neutral).", "Start the vehicle and release the parking brake."]