[thstone]

Try reset ^ first;

Beyond that, I believe that the Tip's have a multi-function switch that senses the position of the gear selector via cables and reports it to the Tip controller. Sounds like either the cables or the multi-function switch aren't working properly so the multifunction switch continues to report that the gear selector is in Reverse.

Also, once the multifunction switch thinks that the gear selector is in either R or D, the Tip controller releases the solenoid which prevents shifting the car into R or D without your foot on the brake.