This is an alarm system fault. Try disconnecting the car battery for at least ten minutes ( make sure you have radio code etc.).
When these cars were new we were re-programming the BCMs on every Vectra-C with a GID showing the 'Check safeguard' message for a pastime, although this may not be the cause in your case.
Another fault I have been coming across lately is that if the codes reveal a fault with the 'Datalink comms' circuit, in other words the ultrasonics unit in the roof, I have been replacing headlining looms due to a break in the printed circuits.
ilexa
September 2009