This code is for the lift and tilt spool locks on the control valve. I am guessing that you have a bad coil or a short in the harness. Most likely once the coil heats up, it is shorting out. If you get the code to come up again disconnect one of the coils and cycle the key. If the code goes away...
If you are seeing "Shtdn 62.1", I think you might be holding the wrong button. I think it is the Pressure relief button that shows the version of software when you press and hold it. It is most likely shuting down because of low hydraulic charge pressure.
Press and hold the lights button to see the active codes. There are 4 things that could be wrong, 1 - the wire harness, 2 - the actuator, 3 - valve/spool, 4 - the controller. Most often I would say it is either the harness or contamination in the valve. Switch the connectors on your lift and...