For the uninitiated with a similar prob., there is plenty on this if you do a search, but the main culprit can be a faulty connector to the air bag underneath the dash. These connectors are known not to be of top quality, and the circuit can be disconnected by a jolt, or, simply closing a door harder than usual. Best get this checked out, as air-bags will not deploy in the event of an accident. The SRS and '!' can be distinguished by TechII - I have known this done for free by local Saab indie garages - or, maybe a trip to Autozone.
HTH
