This control unit is located under the battery tray.
This unit is manufactured in Germany by Wehrleh, the OEM supplier to Mercedes.
This is the newest (third revision) and most current version of this unit. It is considerably smaller than the earlier units and has automatic circuit breaker type reset, unlike the first units that came with the vehicles, when new.
The original units had internal fusible links that would burn out and the entire unit had to be thrown away and replaced.