Mercedes-Benz 2005 M-Class Operator's Manual page 252

Practical hints
What to do if ...
Problem
É
The red brake warning lamp
comes on while driving.
É
The red brake warning lamp
comes on while driving and you
hear a warning sound.
Warning!
Driving with the brake warning lamp illumi-
nated can result in an accident. Have your
brake system checked immediately if the
brake warning lamp stays on. Don't add
brake fluid before checking the brake sys-
tem. Overfilling the brake fluid reservoir can
result in spilling brake fluid on hot engine
parts and the brake fluid catching fire. You
can be seriously burned.
250
Possible cause
There is insufficient brake fluid in the reser-
voir.
You are driving with the parking brake set.
!
G
If you find that the brake fluid in the
brake fluid reservoir has fallen to the
minimum mark or below, have the
brake system checked for brake pad
thickness and leaks.
Suggested solution
Risk of accident! Carefully stop the
vehicle and notify an authorized
Mercedes-Benz Light Truck Center.
Do not add brake fluid! This will not
solve the problem.
Release the parking brake
( page 48).