My Land Rover shifted itself into "downhill" mode. What can I do?

My 2003 Land Rover Freelander shifted itself into "downhill" mode. I didn't push the button (even accidentally) or move the gearshift over to the "sport" mode. I was just leaving a parking spot by the road and it suddenly did it. The code "F 4" (or "4 F") is flashing on the left side of the odometer window. The yellow "Check Engine Soon" and the yellow "downhill mode" indicator (with an exclamation mark) are both lit. The car is very sluggish as I leave a standing stop, including stop lights. A quick merge into traffic is impossible.

Naturally, my closest dealer is 2.5 hours away since I moved here. I called several local transmission places, but none service Land Rovers. Two, however, feel it could be a computer problem rather than a trannie problem.

Is there anything I can do myself to try resetting/rebooting the computer? If not, is it OK to drive the car for any distance in this mode? I would either go to a repair shop 25 minutes away and hope they can fix it, as they handle Land Rovers, or 2.5 hours to the dealer. Both destinations would include highway driving.

I sure appreciate any advice anyone who has Land Rover experience can offer. Thank you!