Diagnostic Module Kaput

[ScotzBenz]

1992 400E 124 034, 119 975, 200,064 miles:
On my way out of town a couple of weeks ago, check engine light comes on. Since heading in the direction of Mercedes dealership/service, get in for a diagnostic (no other evidence of an issue).

My first question: is this automatically triggered by the rollover to 200k mi? No. In we go, and a couple hours later, the diagnosis: my DM is bad - A $1380 part that's vehicle specific and needs to be factory programmed for my car at MB Deutschland. "Then we can check for error messages" I'm told.

The check engine light having been shut off when in the shop, came back on again yesterday. Can anyone assure me (give me hope) that there's another alternative to shelling out $$s to figure out if I'm going to have to shell out $$s (sounding like a microsoft windows issue isn't it).

Thanks,

Scotz on the coast