Thanks Arthur for your suggestions

I actually may need the Homemade code reader if the rebuilt ETA doesn't help
So here's the link to the DIY reader
Benzworld.org - Mercedes-Benz Discussion Forum - View Single Post - Homemade diagnostic code reader for MY90-95

And here's the link to Arthur's DTC List
http://www.peachparts.com/shopforum/tech-help/107630-e320-16-pin-dtc-charts-inc-pin-8-pin-14-a.html