I worked for Crown as a Field Technician for many years, although no longer working for Crown, I'll do my best from memory.

You can access the Calibration Menu through the Operator's Display, using the Up and Down buttons.
You'll need to scroll to the Password menu and enter the 4 digit code: 2311.
If you can't find the Password Menu after the keyswitch has been closed and forklift is powered up, then you'll need to start from the beginning.
1-open keyswitch, press and hold the Up and Down buttons at the same time and close keyswitch and keep pressing the buttons until you see Password on the display.
2- type 2311 and press Enter button.
3-scroll to the Calibration Menu, press Enter button.
4-Scroll up or down to Travel Pot, and follow instructions on the screen. Do the same thing for Lift/Lower Pot and also the Sideshift Pot.

*Pot is street slang for Potentiometer.

I'll bet that the Travel Pot is out of Calibration, but you really do need to view the voltages for all 3 Pots.