You have activated the anti-theft system. Mine did that once I think I had accidentally locked it from inside the car using the infrared key. When you try to start it the car thinks it's being stolen. You'll need to unlock it with the IR key THEN start it.
RIP "Betsy" (Oo=*=oO)
'96 E 3 2 0 (W 2 1 0) M 1 0 4 (Totalled)
Spaces in sig so as not to screw up the SEARCH; every time someone searches for that MB they don't want my sig!
2004 Audi A8L
'98 VW Passat 1.8T 5M
'87 Alfa Romeo Milano 2.5L 5M
'67 Impala convertible, 327cid