PGM 16.6 Mire and assualts

[Blackcloud6]

What happens when a mire prone vehicle assaults into terrain that would cause the mire check?

Do you check for mire since this is a Fire command? I think so as 16.6 uses the word "enters" and not "moves." But if so and the AFV mires, does it still count in the assault? Nothing says it doesn't but the unit is marked with a Fired/moved as result of the mire.

Also, in subsequent turns while still mired, can that unit fire or must it attempt to un-mire?