T180 39-16 & 39-13 left Joystick error

[OTH_stables]

Our T180 is throwing 39-16 and 39-13 left joystick errors. I'm guessing to repair this the path is to check the wiring & connectors on the joystick. Is that right? Has anyone else run into this - if so, how did you resolve it?
Thanks!