Ah, from this forum I got the following for a '93 190e 2.3:

1 No fault found
2 Throttle position switch - wide open throttle fault
3 Engine coolant temperature sensor
4 Air flow sensor position indicator
5 Oxygen sensor
6 Not used
7 TD-signal (rpm)
8 Altitude correction capsule
9 Electronic hydraulic actuator (EHA)
10 Throttle position switch - closed throttle position fault (idle)
12 Exhaust gas recirculation temperature sensor

So when I counted the flashes I got 12! Of course I can't find a part called an "EGR Temp Sensor"...so I was interested in anyone elses solution to this. Could it be plugged vacuum hoses, the EGR Valve itself ($200+) or something else?

Steve