Key will not turn on 2008 chevy hhr

There are two situations that are close to what you describe.

First, is your key STUCK in the ignition? if so, there's a little panel under the steering column, open that, and feel round under there for the latch to release the key. I don't remember what the dealer SAID the issue was, but it was solved with one of many steering column replacements for a different problem.

If the key goes in and out, but won't turn the cylinder... you may have a bad cylinder, a ruined key(bent? run over by car? goobered up lands? plain worn out?) Or, your steering lock is engaged. If it's the first, that's a mechanic replacment(hopefully dealer covered). The second? get a new key. The third? Hold some tension on the steering wheel and turn the key.

Finally, if your battery is dead, or your solenoid is shot, the key won't turn/release either. Use the stuck key removal method, so you can lock your car while waiting on dealer repair.

You will need to take off the wheel panels and undo the ignition switch and there will be a lil button on the back press that and it should release the key so it will turn..