Does anyone know if codes are displayed on the console or do I need a handset.

This machine , while operating a short distance shuts down traction and displays a wrench code. Turning off the key and turning back on resets the machine but will shut again when driving.

I removed the top cover and gently tapped the wiring leading to/from the joystick handle at the connections looking for an intermittent issue while driving. Suddenly, when tapping the wires the truck lurched forward into high speed. This happened several times

Has this issue ever occurred w/ anyone else, wiring would seem to a problem but a high speed jolt seems out of the ordinary.

thank you for any advise.