Does P0500 fault code problems go through the ignition switch

Question

On my 1999 F250 super duty I have a "check engine soon light" on and when it was downloaded they found a P0500 code which refers to the "vehicle speed sensor". This is a repeat problem where they have changed the speed sensor about eight months ago. Now my dealer says they need to fix the main ignition switch before proceding to more troubleshooting. Does this sound right?