According to the wiring diagram you do have DAS:
http://www.autolib.diakom.ru/CAR/Mercedes-Benz/1997/S500/SYSTEM%20WIRING%20DIAGRAMS/6413.pdf
The DAS cannot be defeated as far as I know. If the car runs for 1-2 seconds and then dies, it's probably the DAS.
You also have a starter lock-out relay that would prevent the starter from engaging.
Good Luck,