If it is standard, it is the linkage. If auto, the trans needs overhauled.
check the recalls alot of problems with the trans
The sensor is stuck if the bottle is full. Just shake it up, it will unstuck.
check your transmission fluid or it may be something electrical if your cavalier transmission is run by electronics. If not it may be a sun gear inside the transmission so you may need to get the transmission rebuilt.
If your van won't go into reverse, the transmission might be stuck. It could also be low on transmission fluid.
It sounds like the transmission shifter linkage is disconnected.
I would replace the thermostat. This sounds like the thermostat is stuck open.
Either lubricate or replace the cables Remove rear wheels to lubricate all contact points
your transmission is stuck in what we call limp mode. Take it to a transmission shop and have an electrical scan done. Does your speedometer work or not ? If not then it could be as simple as a output speed sensor or broken wire
Stuck how? Lock? Door?
Check these three things; Bad door jam switch ( stuck?), bad bulb, blown fuse.
the window motor might be bad or there is not of power in your cords to power it
Same thing happened to my friend - there is an "H" shaped (sort of) bracked just below the boot for the shifter - the bolt on the right hand side had dropped off and the left one was loose enough for the plate to move (he was stuck in reverse)... new nut & bolt and a good tighten and he was able to get out of the mall parking lot... .