I bought a used 1996 Chevy Suburban 1500 in Mexico, but it was orginally sold in Califonria. It stays at my house on the Pacific coast.

It came with one ignition key and a remote. I duplicated the key, and it worked fine, and my friends were able to use the dupe to drive the car while I am back in the states. I brought the remote back home with me.

I just heard from them and they are unable to start the vehicle. Whenever they insert the key, an alam goes off. What's the deal?

Anyone know how to fix this?

Thanks!