Mercedes-Benz M-Class 2008 Owners Manual - Manual (Page 199)

198
Controls in detail
Transfer case
! Operational or performance test must only
be conducted on a two-axle dynamometer. If
such tests are necessary, contact an authorized
Mercedes-Benz Light Truck Center. You could
otherwise seriously damage the brake system or
the transfer case which is not covered by the
Mercedes-Benz Limited Warranty.
!
Because the ESP ® operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position 0 or 1 or
KEYLESS-GO* start/stop button in
position 0 or 1) when testing the parking brake
on a brake test dynamometer and such testing
should be no longer than 10 seconds.
Active braking action through the ESP ® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.
i The vehicle is equipped with permanent
four-wheel drive. Both the front and rear axles
are powered at all times when the vehicle is
being operated.