The key from a 2001 GMC Savannah opened the doors of our 2002 Chevy Express (same van model, different badges). Though the Express key could not open the Savann

The key from a 2001 GMC Savannah opened the doors of our 2002 Chevy Express (same van model, different badges). Though the Express key could not open the Savannah. Either key did not work in each others ignition lock.