i set the alarm and it may be two steps or in the middle of the night when the alarm goes off. Message on console "theft protection failure, contact service". Even fif i clear the message, and DON'T lock the car, when i restart the car, that message will display
the alarm keeps going off for no apparent reason on 2006 Saab 9-3
Low battery in the key remote caused mine to do that.
1 more answer , 1 more comment
Corrosion on a ground, possibly a loose faulty connection at a door or hood switch or faulty control module. A shop with good Saab diagnostic info would probably be the most desirable method of repair.I had a 2009 Odyssey with the same proble and it was only one year old at the time , the problem was corrosion on a ground bolt in the passenger side sliding door , that would allow a change in the resistance in the circuit at random and set the alarm off.
I have a 2007 Saab 9-3 and the rear window regulator on the driver side broke, when I disconnected the plugs that control the switches I got that message "Theft Protection Failure". More likely you have a loose connection in one of your doors. You have to remove the inner panel and take a look.