
Display messages
Possible causes/consequences and
M
M
Solutions
Active Brake
Active Brake
Assist Functions
Assist Functions
Currently Limited
Currently Limited
See Operator's Man‐
See Operator's Man‐
ual
ual
Active Brake Assist is temporarily inoperative.
Possible causes are:
R
the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio stations
or other sources of electromagnetic radiation
R
the system is outside the operating temperature range
R
the on-board voltage is too low
When the causes stated above no longer apply, the display message
disappears.
Active Brake Assist is operational again.
If the display message does not disappear:
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X
Secure the vehicle against rolling away (
Y
page 145).
X
Restart the engine.
Active Brake
Active Brake
Assist: System
Assist: System
Inoperative
Inoperative
Active Brake Assist is unavailable due to a malfunction. Situation-
dependent braking assistance may also have failed.
X
Visit a qualified specialist workshop immediately.
Radar Sensors
Radar Sensors
Dirty See Opera‐
Dirty See Opera‐
tor's Manual
tor's Manual
The radar sensor system is malfunctioning.
Possible causes are:
R
dirt on sensors
R
heavy rain or snow
R
when driving on inter-urban roads without traffic or infrastructure,
e.g. in desert-like areas
At least one driving system or driving safety system is malfunction-
ing or is temporarily unavailable:
R
Active Brake Assist
R
Active Distance Assist DISTRONIC
A warning tone also sounds.
Once the cause of the problem is no longer present, the driving and
drive safety systems will be available again. The display message
disappears.
If the display message does not disappear:
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X
Secure the vehicle against rolling away (
Y
page 145).
X
Switch off the engine.
X
Clean all sensors (
Y
page 282).
X
Restart the engine.
The display message disappears.
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Display messages
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