See also:

Mercedes-Benz M-Class Owners Manual
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EBD (electronic brake force distribution)
Observe the "Important safety notes" section EBD monitors and controls the brake pressure on the rear wheels to improve driving stability while braking. WARNING If EBD has malfu ...

Wet roads
WARNING After driving in heavy rain for some time without applying the brakes or through water deep enough to wet brake components, the first braking action may be somewhat reduced. You have ...