Pinpoint Test K: LFC 51/DTC B2691 - Seat Belt Buckle Switch Circuit Fault - Front Driver Side: Notes
WARNING: This page is about a different car, the 2008 Ford RV Cutaway, 2008 Ford Econoline, 2008 Ford E450 Super Duty, and 2008 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
Refer to SYSTEM WIRING DIAGRAMS - E350 SUPER DUTY , Supplemental Restraint System for schematic and connector information.