No matter what gear I am in it says I am in 1st?

I just bought a 2001 Mercury Villager Estate last night and I didn't notice before I bought it that no matter if I am in park, reverse, neutral...etc it always says I am in 1st on the dash. The van runs perfect so I don't think it's really a problem as much as an annoyance. Does anyone know how to fix it and how hard that would be?