I have a 92CE in Costal Northern California and my SRS light stays on briefly after starting at 60 degrees/Sea Level. While visiting family in Auburn at 20 degrees/2000ft,
it came on and stayed on for a few min. after startup! An independent MBZ shop told me the most common reason for this is low battery voltage. The battery appears to be original and since the light returned to it's previous behavior at home, I'm sure this is my problem. You're smart to investigate first - this could be an open checkbook for your favorite authorized Mercedes Benz dealer.
Scott in Monterey