In our daily work, we use VVDI MB Tool to program Mercedes-Benz keys, renew ecu/gearbox. Most of these control units need to be removed from the car and connected with a test harness.
Usually W164 w221 w204 w207 w221 w216, we have the eis/elv test line cables. However, some models are not commonly used or old models of vehicles do not have. At this time, you can check the following diagram as reference.
W639 EIS and ELV
4.W211 W209 EIS ELV
5.Gear lever computer
9.W215 W203 W230 EIS
10.W202 W208 W210 EIS ELV
11.W204 W207 W212 EIS ELV
It should be noted that the wiring must be strictly in accordance with the markings in the figure, otherwise it will easily cause damage to the control unit and equipment.