ASR = Automatic Slip Reduction as in traction control control brakes at all 4 wheels. It's connected to the ABS system and the Tempomat cruise control system.

MBs require specific fluids for various systems. My 94 e320 uses Power Steering fluid FEBI 08972 and the hydraulic fluid Febi 2615 used in the self leveling suspension although they use the same pump. PS fluid into the top of pump, self leveling fluid into its reservoir. PS pump has internal float, don't overfill!

Check specific fluid requirements for your year and model to be sure.

They also use specific spark pugs among other items. Don't vary from the spec!