1997 Lincoln Continental Speedometer / Shifting problem

Hello,

I just purchased a 1997 Lincoln Continental. The speedometer is not functioning and the vehicle seems to refuse to shift out of 1st gear. Computer returns code U1039 which seems to indicate a problem with the vehicle speed sensor, but I am getting conflicting information regarding the location of this sensor or if it even has one. From what I've been reading, some people have reported problems with the ABS control computer, although I don't seem to be having all of the same symptoms (no ABS light, no traction control light).

When watching the speed data with my computer I can see it does occasionally read a value (typically when you hit a good bump), but the value is completely meaningless (30mph reading when the GPS says it's well under 10)

What sensors are most likely to cause a speedometer AND shifting problem without illuminating an ABS light? Where are the sensors physically located? It might also be worth noting that the car doesn't seem to want to display it's odometer either (just shows )