Lost Key To My 2000 Cadillac DeVille

I don't think today's ECU Controlled engine systems would start up with no ignition switch key......., You should take ur Cadillac registration, your photo ID and go to the closest GMC dealer, the only ones able to make a copy of that computer coded key you nowhere can't find. Thanks, I hope this help.

No you cannot start it without the correct key, trying to do so will activate the security system and then your stuck. The cheapest will be what we call a smart locksmith, they have the tools and equipment to pick out the key code and then program the system to recognize the new parts. Good luck