
Display messages Possible causes/consequences and
0004 Solutions
The red
0005(USAonly)/000A (Canada only) indicator lamp lights
up.
The powe rsupply for the electric parking brake was interrupted.
X Pull the electric parking brake handle.
or
X Pull away carefully.
or
X Pull the electric parking brake handle until the display message
disappears. The red
0005(USAonly)/000A (Canada only) indicator lamp lights
up .The yellow 0005(USA only)/000A (Canada only) warning lamp
lights up.
The electric parking brake is malfunctioning.
X Switch off the ignition and turn it back on.
X Engage or release the electric parking brake.
or
X Pull away carefully.
X Visit a qualified specialist workshop. The yellow
0005(USA only)/000A (Canada only) warning lamp
lights up. The red 0005(USA only)/000A (Canada only) indicator
lamp flashes for approximately ten seconds after the electric
parking brake has been applied or released. It then goes out or
remains lit.
The electric parking brake is malfunctioning, e.g. because of
overvoltage or undervoltage.
X Pull away carefully.
X Visit a qualified specialist workshop.
If there is overvoltage or undervoltage:
X Remove the cause for the overvoltage or undervoltage, e.g. by
charging the battery or restarting the engine.
X Switch the ignition off and on, and then engage or release the
electric parking brake.
If this does not release the electric parking brake:
X Do not drive on.
X Consult a qualified specialist workshop. Display messages
397On-board computer and displays Z

Display messages Possible causes/consequences and
0004 Solutions
The yellow
0005(USA only)/ 000A(Canada only) warning lamp
lights up. The red 0005(USA only)/ 000A(Canada only) indicator
lamp flashes fo rapproximately ten seconds after the electric
parking brake has been applied or released. It then goes out or
remains lit.
The electric parking brake has overheated.
X Allow the vehicle to cool down. Do not engage or release the
electric parking brake during this time.
X Use the folding wheel choc k(Ypage 480 )from the vehicle tool
kit to secure the vehicl eagainst rolling away.
X When the vehicle has cooled down: switch the ignition off and
on again, then engage or release the electric parking brake. 0005(USA
only)000A(Canada
only)
Parking Brake
Inoperative The yellow
0005(USA only)/ 000A(Canada only) warning lamp
lights up. The red 0005(USA only)/000A (Canada only) indicator
lamp flashes for approximately ten seconds after the electric
parking brake has been applied or released. It then goes out or
remains lit.
The electric parking brake is malfunctioning.
X Switch the ignition off and on, and then engage the electric
parking brake.
If it is not possible to engage the electric parking brake:
X Shift the transmission to P.
X Use the folding wheel chock (Y page 480) from the vehicle tool
kit to secure the vehicle against rolling away.
X Consult a qualified specialist workshop. 0005(USA
only)000A(Canada
only)
Turn on the
ignition to
release the
parking brake The red
0005(USA only)/000A (Canada only) indicator lamp lights
up.
You attempted to release the electric parking brake while the
ignition was switched off.
X SmartKey: turn the SmartKey to position 1in the ignition lock.
X KEYLESS-GO: switch on the ignition.398
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
0004 Solutions
000F(USA
only)
0006(Canada
only)
Service See Operator's Manual There is a malfunction in the system. The brak
esystem continues
to operate normally.
X Drive on carefully.
X Visit a qualified specialist workshop. 000F(USA
only)
0006(Canada
only)
Check brake fluid level There is no
tenough brake fluid in the brake fluid reservoir.
Additionally, the red 000F(USA only)/ 0006(Canada only) warning
lamp lights up in the instrument cluster and a warning tone
sounds.
G WARNING
The braking effect may be impaired.
There is a ris kofanaccident.
X Pull ove rand stop the vehicle safely as soo nas possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 327).
X Consult a qualified specialist workshop.
X Do not add brake fluid. This does not correct the malfunction. Display messages Possible causes/consequences and
0004 Solutions
0008
Tele Aid
Inoperative USA only: one or more of the main functions in the mbrace system
are malfunctioning.
Canada only: one or more of the main functions of the TELEAID
system are malfunctioning.
X USA only: have the mbrace system checked at aqualified
specialist workshop.
X Canada only: have the TELEAI Dsystem checked at a qualified
specialist workshop. PRE-SAFE
Inoperative See
Operator's Manual Important function
sof PRE-SAFE ®
have failed .All other occupant
safety systems, e.g. air bags, remain available.
X Visit a qualified specialist workshop immediately. Display messages
399On-board computer and displays Z

Display messages Possible causes/consequences and
0004 Solutions
PRE-SAFE
Functions
currently limited
See Operator's
Manual PRE-SAFE
®
Brake is temporarily inoperative. Possible causes are:
R the DISTRONIC PLUS cover in the radiator trim is dirty
R function is impaired due to heavy rain or snow.
R the sensors in the bumpers are dirty.
R the rada rsensor 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.
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 327).
X Clean the DISTRONIC PLUS cover in the radiator trim
(Y page 474).
X Clean the bumpers (Y page 474).
X Restart the engine.
If the system detects that the sensors are fully operational, the
display message disappears.
PRE-SAFE ®
Brake is operational again. PRE-SAFE
Function limited
See Operator's
Manual PRE-SAFE
®
Brak eisd efective. BAS PLUS or the distanc ewarning
signal may also have failed.
X Visi taqualified specialist workshop. 001A
Restraint system
malfunction
Consult workshop There is a malfunction in the SRS (Supplemental Restraint
System). The
001Awarning lamp also lights up in the instrument
cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 400
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
0004 Solutions
Front-passenger
air bag enabled
See Operator's
Manual The front-passenger air bag is enabled during the journey, even
though:
R
a child, a small adult or an objec tweighing less than the
system's weight threshold is located on the front-passenger
seat.
or
R the front-passenger seat is unoccupied.
The system may detec tobjects or forces applying additional
weight on the seat.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Apply the parking brake.
X Switch the ignition off.
X Open the front-passenger door.
X Remove the child and the child restraint system from the front-
passenger seat.
X If necessary, secure the child in a child restraint system on a
suitable rear seat.
X Make sure that there are no objects on the seat adding to the
weight.
The system may otherwise detec tthe additional weight and
interpret the seat occupant's weight as greater than it actually
is.
X Keep the seat unoccupied, close the front-passenger door and
switch on the ignition.
Observe the 00170016(Y page 54) indicator lamp and the
multifunction display and check the following:
Seat unoccupied and ignition switched on:
R the 00170016 indicator lamp must light up and remain lit.
When the indicator lamp is on, OCS (Y page 54) has disabled
the front-passenger air bag.
R the following display messages must not appearint he
multifunction display: Front Passenger air bag Enabled See Oper. Manual or
Front Passenger air bag Disabled
See Oper. Manual .
X Wait for a period of at least 60 seconds until the necessary
system checks have been completed.
X Make sure that the display messages do not appearint he
multifunction display.
If the conditions are not fulfilled, the system is not operating
correctly. 402
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
0004 Solutions
Front-passenger
air bag disabled
See Operator's
Manual The front-passenger air bag is disabled during the journey, even
though:
R
an adult
or
R a person larger than a certain size is occupying the front-
passenger seat.
If additional forces are applied to the seat, the system may
interpret the occupant's weight as lowe rthan it actually is.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Apply the parking brake.
X Switch the ignition off.
X Have the occupant get out of the vehicle.
X Keep the seat unoccupied, close the front-passenger door and
switch on the ignition.
Observe the 00170016(Y page 54) indicator lamp and the
multifunction display and check the following:
Seat unoccupied and ignition switched on:
R the 00170016 indicator lamp must light up and remain lit.
When the indicator lamp is on, OCS (Y page 54) has disabled
the front-passenger air bag.
R the following display messages must not appearint he
multifunction display: Front Passenger air bag Enabled See Oper. Manual or
Front Passenger air bag Disabled
See Oper. Manual .
X Wait for a period of at least 60 seconds until the necessary
system checks have been completed.
X Make sure that the display messages do not appearint he
multifunction display.
If these conditions are fulfilled, the front-passenger seat can be
occupied again. Whether the 00170016indicator lamp
remains lit or goes out depends on how OCS classifies the
occupant.
If the conditions are not fulfilled, the system is not operating
correctly.
X Visit a qualified specialist workshop immediately. 404
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
0004 Solutions
Blind Spot Assist
Currently
Unavailable See
Operator's Manual
or
Active Blind Spot Assist
Currently
Unavailable See
Operator's Manual Blind Spot Assist or Active Blind Spot Assist is temporarily
inoperative. Possible causes are:
R
the sensors are dirty.
R function is impaired due to heavy rain or snow.
R the rada rsensor system is outside the operating temperature
range.
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.
The yellow 000Aindicator lamps also light up in the exterior
mirrors.
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 Apply the electric parkin gbrake.
X Clean the sensors (Y page 474).
X Restart the engine.
If the system detects that the sensors are fully operational, the
display message disappears.
Blind Spot Assist or Active Blind Spot Assist is operational again. Blind Spot Assist
Inoperative or
Active Blind Spot Assist Inoperative Blind Spot Assist or Active Blind Spot Assist is defective.
The yellow
000Aindicator lamps also light up in the exterior
mirrors.
X Visi taqualified specialist workshop. Parking Guidance
Inoperative Parking Guidance is malfunctioning (
Ypage 353).
X Restart the engine.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. 416
Display messagesOn-board computer and displays

Problem Possible causes/consequences and
0004 Solutions
X
Carefully drive a short distance on a suitable stretch of road,
making slight steering movements at a speed above 12 mph
(20 km/h).
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 0015
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds. EBD is malfunctioning. Therefore, ABS, BAS, BAS PLUS, ESP
®
,
PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD function and hill start
assist are also unavailable, for example.
ATTENTION ASSIST 21
is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely
affected. The braking distance in an emergency braking situation
can increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 21
Not available on hybrid vehicles. Warning and indicator lamps in the instrument cluster
429On-board computer and displays Z