10. The final operation is verifying on the push-button control panel that the speed sensor is working. The manual will ask you to drive the car slowly while the display reads out vehicle speed. If it’s working, you will not be able to shift into “P” when the car is rolling faster than 1 mph, or “R” when the car is faster than 3 mph. If you’re just installing the push-button shifter only, you are finished!