Un lock streening wheel

I have 2002 cadilac deville, The streening wheel is locked and I can’t start the car.

can you help me how to unlock it.

I conclude the main problem is you can’t turn the key to “start” position.

I will ask just so we can say we covered the easy stuff. Correct key? (have you tried your spare?) Wheels straignt ahead? (have you tried wiggling the steering wheel?). If yes to all you need a lock cylinder (pull the air bag and steering wheel and lock plate to get to it) Your choice locksmith or mechanic,preferably someone experienced in air bags and lock cylinder removal techniques.

Does the engine turn over when you try to start it? Can you move the shift lever out of park? If the answer is no to both questions, you may need a new battery.