My wifes GLK 350, 12,000 miles, pristine condition was taken to a MB dealership for an airbag recall and ECU program update per MB campaign. Nomisdues with the vehicke at all before taking it in. After leaving the deakership I drove home and after approx 25 miles my engine light came on (fuel injection module performance) and my ECO no longer worked. Completting another drive cycle I traced the origin back to the dealership. I retuned it to them and they reflashed the ECU. I replaced the Aux battery as well. So now my OBD2 reader when pluggled in initially gets no activity on the diagnostics screen, if I esc and hit diagnostics again the proper indicators appear. But my ECO still diesnt work. I believe these issues go back to the orogram update. Any advice?