If the MFD has a message  that says "DAU Not Configured for Aircraft Type" or something to that effect. Have shop check the Aircraft Type Designator / Strapping wire per the Piper Maintenance Manual.

This is nothing more than a ground wire that configures the aircraft type.

For Example

Piper Seminole  DAU Connector P103-9 to airframe ground

Piper Seneca V DAU Connector P103-9&10 to airframe ground

Piper Warrior III DAU Connector P305 - 8, 9, & 10 to airframe ground

So as you can see the Aircraft Type Designator is nothing more than a strapping wire to ground.