The AWD mode works on it's own on dry pavement. If the computer senses hard acceleration and a high off-set of steering input, it will feather torque to the rear wheels as it deems necessary. This occurs without any slip actually ocurring. As far as Brake-Lock on the FDI...The Traction Control System applies brake pressure to the tire on the inside of the turn when it detects a slide, pulling the vehicle into the desired direction. This is no different than what an FDII does in a loss of traction situation, and relies on the same basic programming to accomplish it. The major difference seems to be that the FDII will enable this feature at low speed, in a straight line. The ESP system does this too, on the FDI, but it takes a significantly higher amount of wheel spin to do it. I have experienced this first-hand in deep snow with my FDI. You can see the snow roostertails switching from side to side and FEEL the Jeep jumping around as it switches side to side with power. On the torque split question outlined in an earlier post, if the front tires are on a relatively higher traction surface (Snow), and the rears are on a lower one (ice), and the system is in Lock mode, the low-traction axle will spin only as much as the high-traction axle. A 50/50 split. If the rears are in a ditch, and the front is on the pavement, it will walk out or spin the fronts AND rears. Mind you, there seems to be a safety feature built into the programming to prevent damge to the drivetrain in these situations. This safety program cuts power to the engine. There are lots of posts on this subject. I have had this happen on a hill in deep snow. I switched to ESP full-off, rolled backward a little, then pulled the trigger in drive. I broke the tires loose and the Pat climbed the rest of the hill like a scalded mountain goat.
