My sunroof won't close

Impossible to answer. All questions in this category need 'year make model' as the first three words.

Google

year make model sunroof won't close

https://www.google.com/search?q=%E2%80%8Byear+make+model+sunroof+won%27t+close

All sunroofs can't be closed manually. Remove the plug and use a screwdriver of power driver.

..

Question edited to add maker, and correct 'completely'.

This is a known issue. See the link and videos.

https://www.google.com/search?q=Buick+LaCrosse+sunroof+won%27t+fully+close

..

1. Place the ignition switch in the ON position.
2. Push and hold the sunroof switch toward 2 . Once the sunroof has reached the full tilt position, release the switch. Push and hold the switch toward the 2 position again. After a delay of four seconds, the sunroof will make a small movement and backup.
3. Release the switch.
4. Within 5 seconds of releasing the switch, push and continuously hold the switch toward 2 . The sunroof will move from the tilt position to the open position and back to the close position.

This is an electrical problem. Check fuses and replace if necessary.

pull down the panel that is directly in front of the sun roof and manually close it.

There should be a crank on your fuse box cover {hexagonal section}. That is the manual closer for sunroof. You have to take off cover for readong/interior light to access the cranking point.

Some sunroofs have a open switch like the drivers window. You push it and the window will open automaticly. The button on your sunroof could be jammed so even though you can close it as soon as you release it, it will auto open on it's own.

you may be able to take the switch apart and clean it. if that doesn't work get two pieces of wire and use them to jump the plug and by pass it all together just to get it closed

It can be faulty motor or loose wiring issue or faulty /weak sunroof controlling switch or there is some blockage for sunroof to come down to close or sunroof out of its track the headliner is out of its way.There re many possibilities.All this basics needs to be checked.For further troubleshooting,go through this help link:----
Click the link mentioned below:------
How to Manually Close the Sunroof ? http://howtobyme.blogspot.in/2012/05/how-to-manually-close-sunroof-on-2001.html

-------------
Sunroof Stuck open? http://howtobyme.blogspot.in/2012/05/2001-lexus-is300-sunroof-stuck-open.html

----------
How to manually close Sunroof on Navigator? http://technoanswers.blogspot.com/2012/01/how-to-manually-close-sunroof-on-2000.html

----------
This will help.
Thanks.

Please read my other suggestion.