Tl* the contact owns a 2012 lincoln navigator. while driving 25 mph, the vehicle downshifted from second to first gear without warning. the vehicle was taken to robert hudson ford lincoln mercury (2316 1st ave se, moultrie, ga 31788, (229) 985-6603) where it was diagnosed that the pcm needed recalibaration. the vehicle was repaired; however, the software update failed to correct the failure. additionally, the contact stated that the vehicle was difficult to shift from park to the drive gear. the contact stated that the vehicle was repaired, but the failure recurred. the contact stated that the vehicle was currently being repaired again for both failures. on several occasions while driving, the electrical system failed and caused the vehicle to stall. the contact stated that the instrument cluster, interior lighting, and exterior lighting failed. the manufacturer was notified of the failures and provided case number: cas-13124389. the approximate failure mileage was 30,000.