I recall some case like that.
Someone must have "played" with the truck and in settings menu activated the pin demand.
The issue is, that it makes sense only, when the you have the display with the keyboard.

When there's no keyboard, the truck is out.

How to solve it?
I don't remember exactly the order, but it goes like this:

Start up the truck from the beginning (battery, main switch, key switch),
connect the notebook with the Pathfinder,
go to settings,
go to display,
find the pin demand menu (as far as I remember there are three options)
choose "desactivate pin",
Reset the truck (key switch, main switch, battery plug).

As far as I remember, the operation should be done quickly after reset, for some short time after it, the system is accepts the adjustments.

I'll check in my old files, if there's some special issue concerning this, and let you know.