As Benzmac said this has digital system computers that have a live data stream that can be read just like dealers do. Not just faults but sensor imputs & actual values as engine runs. Some of the computers will support impulse testing for trouble codes w/analog tester. Tools like this run at least $2000.
MERCEDES BENZ MASTER GUILD TECHNICIAN
ASE MASTER TECHNICIAN
27 YEARS DEALER M.B. Shopforeman
190E 2.3 ITS RACECAR
1986 190E 16V