its some kind of fault because i've had/got problems with mine.
i've had mine 5 years and the passenger side has always worked fine, if you hold the button down for about 1 sec and release it either opens or closes fully.
drivers side worked initially, then stopped, and has had short spells of working since but 95% of time it hasn't!!! works fine in short dabs up and down, has always worked going fully down (auto) but not up. goes up so far than back down or up to top then part way down......very annoying!!!! i would love to know if someone knows why?

i've tried lubricating the glass/runners etc. etc. some say motor but surely if the motor was the problem you would get other problems or it would pack up altogether???
i think it must be some sort of switch/sensor because they have a safety mechanism so they stop if you had you arm in the way etc.!!!
both windows open or close fully using the auto feature by holding the key in locked/locked position but sunroof doesn't?!?!? it has done intermittantly......interestingly it seemed to (auto) close when the window was functioning fully??? maybe related or coincidence?!?!......i don't know???