I have a 2011 Cadillac CTS sudden loss of power.

Hello there, this is Dusty from the Car Genius team at RepairPal. I'm sorry to hear about the trouble you're experiencing with your Cadillac; experiencing power loss on the freeway and the engine locking up is scary. Now, you've been left with significant concern, and rightly so. The fact that the engine isn't turning over and is just clicking indicates the possibility of it being seized, but there could still be electrical issues at fault here. I strongly advise having a professional technician thoroughly inspect your Cadillac to avoid getting ahead of ourselves. They can conduct a comprehensive diagnosis to pinpoint the exact cause of the issue. Taking prompt action with diagnosis and repair can help prevent further damage and higher repair costs. If you have any other questions or would like help finding a RepairPal Certified shop in your area, call us! 877-913-1554