transmission won't shift out of first gear.

The speedometer also doesn't work. Could this be the speed sensor, abs sensors, or a combination of them? Or am I looking at larger problems? The engine runs fine, the transmission engages smoothly in reverse and forward gears, it just won't shift out of first. I've read that the speed sensor could be to blame and the antilock brake sensors or psom could also be at fault. The speedometer also stopped working at the same time. All other gauges work properly.