I must diappoint you.
I live in Germany, about 70 miles south of hannover.
MB S210 is my daily driver, but the classic D-Jet-car is an Opel (GM) Diplomat B-model.
I bought the Ditron some months ago on ebay from switzerland - the seller told me he had bought it many years ago at ebay USA.
It has been much more easy to find informations about the D-Jet system in the USA than in Germany for many years, therefore I know some US-sites, too.
Now we have a platform in Germany, German and English languageoldtimer.tips
. We try to find out everything about the system and how to repair the components. We are hobbyists mostly MB, but also BMW, VW, Opel, Porsche, Renault, Citroen, Lancia... all the car brands D-Jetronic was installed in.
I don't really need the Ditron 812D to diagnose or optimize my car - I own other testers.
But I am interested in its functions.
Hope that someone still has the instruction for the tester...
My tester has serial #119
- don't know how many were built at all.
In Germany we say 'hope dies last'.