The description sounds like the tumblers inside the cylinder have either stuck and jammed or been damaged. If that is the case the first thing to try is to turn the steering wheel one direction or the other and see if the locking pin is causing the binding, if the car was parked with the wheels turned the lock can bind up and it will not allow the key to move.
If it still refuses to move and there hasn't been any other issues like hard turning or similar prior to this time it will likely require the steering column be taking apart and determine what is binding. It could be the cylinder itself or the steering lock. The problem is that removal of the cylinder without damaging anything requires that it be able to turn in the housing. Replacement if it cannot turn requires that the entire lock housing (yellow item in image) be replaced.
To do that and still use your current keys requires that the replacement key cylinder be re-keyed to match your current keys. Or if you can gently cut the lock housing open you can sometimes salvage the original cylinder, if it isn't the damaged part.
You disconnect the battery then remove the airbag, then the steering wheel and the covers(A) from the column. Then unplug and remove the combination switch(B) by removing screw C and sliding it off.
Next you need to remove the two headless screws red circled items, from the retainer clamp (E), the easiest way is to drill them, the next is to use something like a Dremel to cut a slot or use needle nose vice grips and remove them. Then the lock assemble comes free and you can disconnect it. You can reuse the ignition switch itself and the retainer, the replacement lock housing should come with new bolts that have twist off heads.
Image (Click to make bigger)
Saturday, October 3rd, 2020 AT 10:17 AM