Fail-safe Mode
WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Because both SSE and SSB apply the clutches they control when they are turned OFF, 5th gear is the fail-safe. This transmission defaults to 5th gear when certain failures are detected. 5th gear is provided hydraulically with no electrical input.