Pinpoint Test E: DTC B1681 - PATS Transceiver Module Signal Is Not Received: Notes
WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Refer to appropriate WIRING DIAGRAM ARTICLE, Passive Anti-Theft System for schematic and connector information.