Without a wiring diagram in hand I can't help with pin locations. But, there is only one thing you can do with a generic OBDII scanner. That being communications with the Diagnostic Module. There is only one diagnostic module and it was added for US models to provide OBDII monitoring. The Diagnostic Module is hooked to the HFM, DI, and EA/CC/ISC controllers and monitors all activities relating to the onboard tracking of emiisons related systems.
MB at first didn't incorporate these parameters into it's engine management system until the ME systems came out at which time there are no more Diagnostic Modules or EA/CC/ISC or DI modules. They are all incorporated into the ME module.
Bosch Master, ASE Master, L1
33 years MB technician