2005 Canyon: My son's GMC Canyon ('05) won't allow him to turn ...

SOURCE: the ignition won't turn for a 2003 gmc yukon denali

make sure the wheels are straight.. if you park them with them turned to one side the steering column is under a bind.... if they are turned all the way to the right you will for example have to turn it a little to the left to release pressure as you turn the key...

SOURCE: can't remove key from ignition 2001 gmc jimmy

I dont know how much help this will be, but I'll offer it and let you be the judge.

Ive had this issue before in a different GM vehicle, a Pontiac Grand Prix. The issue turned out to be that the voltage from the battery was low due to corroded terminals. Once that was cleaned up and the voltage restored to normal, the key came out. Come to find out that this was a common issue in that vehicle, voltage goes low, you cant remove the key.

Now, on my vehicle and since yours is a GM product as well I will assume it will hold true for your vehicle too, there is a small hole on the bottom side of the column right in the area of where the ignition key cylinder is. If you have this, you can take a small tool like an allen wrench and push it up in there and that will press on a release mechanism that should allow you to turn the key back to its release position and pull the key out.

Hope this helps.

SOURCE: key stuck in the ignition of 1998 GMC Jimmy

sounds like your shift lever for trans isnt making a tight connection when you put it in park....try shifting it in and out of park several times while trying to remove key......my lincoln does that occasionally and when i take it out of park and then back in it works......just a thought