You need to make sure your drive motor cables are not shorted. Check the under carriage of the machine and see if drive motor cables are not dragging on the ground. Pull battery out and make sure acid corrosion did not dissolve the insulation off the cables. If there okay, unplug the battery for 5 minutes cycle the key and see if your code returns,if so you have a failed drive controller. If you need to test for sure. the controllers can be swapped.