I'm assuming you've changed the HV board in the back?
Some Whirlpool main boards need to know what machine they are in but the new part should have come with whatever instructions you'd need if that was the case. If not the programming code will be on your info tag inside the fridge with the model serial #.

If the display says PE0 or similar you will need to enter model code.

Try pressing freezer temp down and door alarm for a few seconds. Release the freezer down button but hold the door alarm pressed for a few seconds.
If display switches to just PE you are in programming mode.

Press freezer temp down again to verify that you want to program it.

It should say PE0.000 now.

The refrigerator temp keys change the value of the digit to the left of the "." Freezer temp up key is enter to move to next. The "." will move too. Continue until your code is shown.

Then press freezer down until the code flashes. Press any key and that should lock it in. Or you may need to open a fridge door and close it to lock the code in.

Here's a few vids if you like to see it:

https://www.youtube.com/watch?v=fwoLQdcFv1Y

or

https://www.youtube.com/watch?v=7YOOJxrE3DA