I went through this when I replaced mine.

I called Bosch and they told me which numbers would work in my car. The ECU I replaced mine with had a different part #.

Part is also called the ECM by some.

I would suggest buying USED from car-part.com. A new one is over $1,000, you know.

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E