The wiring for the transfer case speed sensor can fail causing sporadic operation of the AWD (All Wheel Drive) system.Google+
Car Problem Reports
Saab 9-7x Sporadic Operation of All Wheel Drive System
Saab 9-7x Problem
Average Mileage: 84,500 mi (84,000 mi - 85,000 mi)
Visitor, 2005 Saab 9-7x, 84,000 mi
NO traction at all in the snow/ice. It is supposed to engage when the back tires slip...only one of my tires is spinning.