5th Gear Failsafe Description
WARNING: This page is about a different car, the 2012 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
When the transaxle has an electrical, hydraulic or mechanical failure, the PCM removes ground (control) from the shift, TCC and LPC solenoids. The uncontrolled solenoids default to their normal states. SSB, SSD and the LPC solenoid are normally high solenoids which means in their normal state, they provide high pressure to the valves they control. This provides only 5th gear with maximum line pressure.