what causes it is the real thin plastic that holds the bar on the elevator. Its easier to go to a junk yard to get a replacement since they will try to sell you the full set at any parts store. The car is not that knew so it shouldn't be that expensive.
the window regulater has a nylon tape that runs the window up and down. the tape can be purchased fromm the parts store
The window will often fall down on a 2001 Nissan Xterra due to a faulty drive motor. This causes the tension that holds the window in place to release.
you could possibly have some sort of shortage
It's the motor assembly that causes the door to go up and down.
Drivers side rear of engine down by the steering column. Wires to a gear.
The engine is not running!
The switch is bad.
yuan dynasty
It's the switch because the motor is getting power to go up but not down.
Your problem isn't specific. Here is a list of causes. please refer this to identify the problem - http://carcarehow.blogspot.com/2011/10/window-does-not-roll-up.html
There could be two causes for this problem. The first being the fuse to that window has blown and the other is window motor is getting weak.
check the transmission mount for being bad.