MERCEDES-BENZ AMG GT ROADSTER 2019 Repair Manual

play messages which may be shown in the
instrument cluster (Y page 175).
Brakes X
If ABS intervenes: continue to depress the
brake pedal vigorously until the braking sit-
uation is over.
X To make a full brake application: depress
the brake pedal with full force.
If ABS intervenes when braking, you will feel a
pulsing in the brake pedal.
The pulsating brake pedal can be an indication
of hazardous road conditions, and functions as a reminder to take extra care while driving. BAS (Brake Assist System)
General information BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 58). G
WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking X
Keep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated. Active Brake Assist
General information i
Observe the "Important safety notes" sec-
tion (Y page 58).
Active Brake Assist consists of a distance warn-
ing function with an autonomous braking func-
tion and a situation-dependent brake boosting
effect.
Active Brake Assist can help you to minimize the risk of a collision with the vehicle traveling in
front or reduce the effects of such a collision.
If Active Brake Assist detects that there is a risk
of collision, you will be warned visually and
acoustically. If you do not react to the visual
collision warning or the warning tone, autono-
mous braking can be initiated in critical situa-
tions. If you apply the brake yourself in a critical situation, Active Brake Assist supports you with
a situation-dependent brake boosting effect.
Important safety notes In particular, the detection of obstacles can be
impaired if:
R There is dirt on the sensors or anything else
covering the sensors
R There is snow or heavy rain
R There is interference by other radar sources
R There are strong radar reflections, for exam-
ple in parking garages
R A narrow vehicle is traveling in front, e.g. a
motorbike
R A vehicle is traveling in front on a different line
R You are driving a new vehicle or servicing on
the Active Brake Assist system has just been
carried out
Observe the important safety notes in the
"Breaking-in notes" section. (Y page 109)
Following damage to the front end of the vehicle, have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow speeds where there is no visible damage to thefront of the vehicle.
Activating/deactivating Active Brake Assist is automatically active after
switching on the ignition. Driving safety systems
59Safety Z

You can activate or deactivate Active Brake
Assist (Y page 168) in the on-board computer.
When deactivated, the distance warning func-
tion and the autonomous braking function are
also deactivated.
If Active Brake Assist is deactivated, the 00D4
symbol appears in the assistance graphic dis-
play.
Distance warning function General information
The distance warning function can help you to
minimize the risk of a front-end collision with a
vehicle ahead or reduce the effects of such a
collision. If the distance warning function
detects that there is a risk of a collision, you will
be warned visually and acoustically.
Important safety notes i Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 58).G
WARNING
The distance warning function does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
The distance warning function may not give
warnings in all critical situations. There is a
risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
Always adapt your speed to suit the prevailing
road and traffic conditions. G
WARNING
The distance warning function cannot always
clearly identify objects and complex traffic
situations.
In such cases, the distance warning function
may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident. Always pay careful attention to the traffic sit-
uation and do not rely solely on the distance
warning function.
Function
Starting at a speed of approximately 4 mph
(7 km/h), the distance warning function warns
you if you rapidly approach a vehicle in front. An intermittent warning tone will then sound, and
the 00BA distance warning lamp will light up in
the instrument cluster.
X Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause the system to display a warning. With the help of the radar sensor system, the
distance warning function can detect obstacles
that are in the path of your vehicle for an exten-
ded period of time.
Up to a speed of approximately 44 mph
(70 km/h), the distance warning function can
also react to stationary obstacles, such as stop-
ped or parked vehicles.
Autonomous braking function If the driver does not react to the distance warn-
ing signal in a critical situation, Active Brake
Assist can assist the driver with the autonomous braking function.
The autonomous braking function:
R gives the driver more time to react to critical
driving situations
R can help the driver to avoid an accident or
R reduces the effects of an accident
Vehicles without Active Distance Assist
DISTRONIC: the autonomous braking function
is available in the following speed ranges:
R 4 - 65 mph (7 - 105 km/h) for moving objects
R 4 - 31 mph (7 - 50 km/h) for stationary
objects 60
Driving safety systemsSafety

Vehicles with Active Distance Assist
DISTRONIC: the autonomous braking function
is available in the following speed ranges:
R 4 - 124 mph (7 - 200 km/h) for moving
objects
R 4 - 31 mph (7 - 50 km/h) for stationary
objects
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause the autonomous braking func-
tion to intervene.
If the autonomous braking function requires a
particularly high braking force, preventative
passenger protection measures (PRE-SAFE ®
)
are activated simultaneously (Y page 54).
Situation-dependent brake boosting
effect General information
i Observe the "Important safety notes" sec-
tion (Y page 58).
With the help of the radar sensor system, Active Brake Assist can detect obstacles that are in the
path of your vehicle for an extended period of
time.
If Active Brake Assist detects a risk of collision
with the vehicle in front, it calculates the brake
pressure necessary to avoid a collision. If you
apply the brakes forcefully, the situation-
dependent brake boosting effect automatically
increases the brake pressure to a degree appro- priate to the traffic situation.
The situation-dependent brake boosting effect
provides braking assistance in hazardous situa-
tions at speeds above 4 mph (7 km/h). It uses
radar sensor technology to assess the traffic
situation.
The situation-dependent brake boosting effect
is capable of reacting to moving objects that
have already been detected as such at least
once over the period of observation, up to a
speed of around 155 mph (250 km/h).
The situation-dependent brake boosting effect
reacts to stationary obstacles up to a speed of
approximately 44 mph (70 km/h).
If the situation-dependent brake boosting effect demands particularly high brake pressure, pre-
ventative passenger protection measures (PRE-
SAFE ®
) are triggered simultaneously
(Y page 54). X
Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if: R you release the brake pedal
R there is no longer any danger of a collision
R no obstacle is detected in front of your vehicle
The situation-dependent brake boosting effect
is then deactivated.
Important safety notes i Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 58). G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist might:
R intervene unnecessarily
R not intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. Terminate the
intervention in a non-critical driving situation.
Due to the nature of the system, complex but
non-critical driving conditions may also cause
Active Brake Assist to intervene.
Even if Active Brake Assist is not available due to a malfunction in the radar sensor system, the
brake system is still available with full brake
boosting effect and BAS. Driving safety systems
61Safety Z

ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes" sec-
tion (Y page 58).
ESP ®
monitors driving stability and traction, i.e.
power transmission between the tires and the
road surface.
If ESP ®
detects that the vehicle is deviating from
the direction desired by the driver, one or more
wheels are braked to stabilize the vehicle. The
engine output is also modified to keep the vehi- cle on the desired course within physical limits.
ESP ®
assists the driver when pulling away on
wet or slippery roads. ESP ®
can also stabilize
the vehicle during braking.
ETS (Electronic Traction System) i
Observe the "Important safety notes" sec-
tion (Y page 58).
ETS traction control is part of ESP ®
.
Traction control brakes the drive wheels indi-
vidually if they spin. This enables you to pull
away and accelerate on slippery surfaces, for
example if the road surface is slippery on one
side. In addition, more drive torque is transfer-
red to the wheel or wheels with traction.
Traction control remains active, even if you
deactivate ESP ®
.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 58). G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further driv- ing safety systems are deactivated. This
increases the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.
ESP ®
is only deactivated if the 00BBwarning
lamp is lit continuously.
When SPORT handling mode is activated, the
0074 warning lamp lights up in the instrument
panel. When the
00BBand0089 warning lamps light up
continuously, ESP ®
is not available due to a mal-
function.
Observe the information on warning lamps
(Y page 201) and display messages which may
be shown in the instrument cluster
(Y page 175).
Only use wheels with the recommended tire
sizes. Only then will ESP ®
function properly.
Characteristics of ESP ® General information
If the 00E5 ESP®
warning lamp goes out before
beginning the journey, ESP ®
is automatically
active.
If ESP ®
intervenes, the 00E5ESP®
warning lamp
flashes in the instrument cluster.
If ESP ®
intervenes:
X Do not deactivate ESP ®
under any circum-
stances.
X Only depress the accelerator pedal as far as
necessary when pulling away.
X Adapt your driving style to suit the prevailing
road and weather conditions.
ECO start/stop function
The ECO start/stop function switches the
engine off automatically when the vehicle stops moving. The engine starts automatically when
the driver wants to pull away again. ESP ®
remains in its previously selected status. Exam-
ple: if ESP ®
was deactivated before the engine
was switched off, ESP ®
remains deactivated
when the engine is switched on again.
Deactivating/activating ESP ® Important safety notes
i Observe the "Important safety notes" sec-
tion (Y page 58).
You can select between the following states of
ESP ®
:
R ESP ®
is activated
R SPORT handling mode is activated
R ESP ®
is deactivated 62
Driving safety systemsSafety

G
WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilizes the vehicle. There is an increased risk
of skidding and an accident.
Only deactivate ESP ®
in the situations descri-
bed in the following. G
WARNING
When SPORT handling mode is activated,
there is a greater risk of skidding and acci-
dents.
Only activate SPORT handling mode in the sit- uations described in the following.
In the following situations, it may be better to
activate SPORT handling mode or deactivate
ESP ®
:
R when using snow chains
R in deep snow
R on sand or gravel
R on specially designated roads when the vehi-
cle's own oversteering and understeering
characteristics are desired
Driving in SPORT handling mode or without
ESP ®
requires an extremely qualified and expe-
rienced driver.
Activate ESP ®
as soon as the situations descri-
bed above no longer apply. ESP ®
will otherwise
not be able to stabilize the vehicle if the vehicle starts to skid or a wheel starts to spin.
! Avoid spinning the driven wheels for an
extended period with ESP ®
deactivated. You
could otherwise damage the drivetrain.
Deactivating/activating ESP ® X
To activate SPORT handling mode: briefly
press button 0043.
The 0074 handling mode warning lamp in the
instrument cluster lights up. The SPORT SPORThan‐
han‐
dling mode
dling mode message appears on the multi-
function display.
X To deactivate SPORT handling mode:
briefly press button
0043.
The 0074 handling mode warning lamp in the
instrument cluster goes out. ESP ®
is activa-
ted
X To deactivate ESP ®
:press button 0043.
The 00BB ESP®
OFF warning lamp in the
instrument cluster lights up. The 00E5OFF OFF
message appears on the multifunction dis-
play.
X To activate ESP ®
:when SPORT handling
mode is activated or ESP ®
is deactivated,
press button 0043.
The 00BB ESP®
OFF warning lamp in the
instrument cluster goes out. The 00E5ON ON
message appears on the multifunction dis-
play.
Characteristics of activated SPORT han-
dling mode
If SPORT handling mode is activated and one or more wheels start to spin, the 00E5ESP®
warn-
ing lamp in the instrument cluster flashes. ESP ®
only stabilizes the vehicle to a limited degree.
When SPORT handling mode is activated:
R ESP ®
only improves driving stability to a limi-
ted degree
R traction control is still activated
R engine torque is no longer limited and the
drive wheels are able to spin
The spinning of the wheels results in a cut for better traction on loose surfaces.
R ESP ®
still provides support when you brake
firmly
Characteristics when ESP ®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the 00E5ESP®
warning lamp in the
instrument cluster flashes. In such situations,
ESP ®
will not stabilize the vehicle.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability
R engine torque is no longer limited and the
drive wheels are able to spin Driving safety systems
63Safety Z

The spinning of the wheels results in a cut for
better traction on loose surfaces.
R traction control is still activated
R Adaptive Brake Assist is unavailable
Active Brake Assist is also not activated if you
brake firmly with assistance from ESP ®
.
R PRE-SAFE ®
is unavailable
PRE-SAFE ®
is also not activated if you brake
firmly with assistance from ESP ®
.
R ESP ®
still provides support when you brake
firmly EBD (electronic brake force distribu-
tion)
General information EBD monitors and controls the brake pressure
on the rear wheels to improve driving stability
while braking.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 58). G
WARNING
If EBD is malfunctioning, the rear wheels can
lock, e.g. under full braking. This increases the risk of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Have the brake system checked at a qualified spe-
cialist workshop.
Observe information regarding indicator and
warning lamps (Y page 201) as well as display
messages (Y page 177). ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety and
offers increased braking comfort. In addition to
the braking function, ADAPTIVE BRAKE also fea-
tures the hill start assist function (Y page 112). Protection against theft
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey. X To activate with KEYLESS-GO start-func-
tion or KEYLESS-GO:
switch the ignition off
and open the driver's door.
X To activate with the SmartKey: remove the
SmartKey from the ignition lock.
X To deactivate: switch on the ignition.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Anyone
can start the engine if a valid SmartKey has been
left inside the vehicle.
i The immobilizer is always deactivated when
you start the engine.
In the event that the engine cannot be started (yet the vehicle's battery is charged), the sys-
tem is not operational. Contact an authorized Mercedes-Benz Center or call
1-800-FOR-MERCedes (in the USA) or
1-800-387-0100 (in Canada). ATA (anti-theft alarm system)
X
To arm: lock the vehicle with the SmartKey or
KEYLESS-GO.
Indicator lamp 0043flashes. The alarm system
is armed after approximately 15 seconds.
X To disarm: unlock the vehicle with the Smart-
Key or KEYLESS-GO.
or X With KEYLESS-GO start function or vehi-
cles with KEYLESS-GO:
press the Start/
Stop button.
The SmartKey must be in the vehicle. 64
Protection against theftSafety

or
X Insert the SmartKey into the ignition lock.
A visual and audible alarm is triggered if the
alarm system is armed and you open:
R a door
R the vehicle with the mechanical key
R the trunk lid
R the hood
R the glove box
X To turn the alarm off with the SmartKey:
press the
0036or0037 button on the Smart-
Key.
The alarm is stopped.
or
X Insert the SmartKey into the ignition lock.
The alarm is stopped.
X To stop the alarm using KEYLESS-GO:
grasp the outside door handle. The SmartKey must be outside the vehicle.
The alarm is stopped.
or
X Press the Start/Stop button. The SmartKey
must be inside the vehicle.
The alarm is stopped.
The alarm is not switched off, even if you close
the open door that triggered it, for example.
i If the alarm continues for more than
30 seconds, the mbrace emergency call sys-
tem automatically notifies the Customer
Assistance Center. This is done either by text
message or data connection.
The emergency call system sends a message
or establishes a data connection provided
that:
R you have subscribed to the mbrace service.
R the mbrace service has been activated
properly.
R the necessary mobile phone network is
available. Protection against theft
65Safety Z

SmartKey
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle, they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shifting the automatic transmission out of
park position P
R Start the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. G
WARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be uninten-
tionally turned in the ignition lock. This could
cause the engine to be switched off. There is a risk of an accident.
Do not attach any heavy or large objects to the
SmartKey. Remove any bulky key rings before
inserting the SmartKey into the ignition lock.
! Keep the SmartKey away from strong mag-
netic fields. Otherwise, the remote control
function could be affected.
Strong magnetic fields can occur in the vicin- ity of powerful electrical installations.
Do not keep the SmartKey: R with electronic devices, e.g. a mobile phone
or another SmartKey
R with metallic objects, e.g. coins or metal foil
R inside metallic objects, e.g. a metal case
This can affect the functionality of the Smart-
Key. Vehicles with KEYLESS-GO start function:
do
not keep the SmartKey in the trunk. Otherwise, the SmartKey may not be detected, e.g. when
starting the engine using the Start/Stop button.
A brief radio connection between the vehicle
and the SmartKey determines whether a valid
SmartKey is in, or in the direct vicinity of, the
vehicle.
This occurs, for example:
R when starting the engine
R while driving
R when using the trunk lid unlocking sensor
R when the external door handles are touched
R during convenience closing SmartKey functions
0043
0037 Locks the vehicle
0044 0054 Opens the trunk lid
0087 0036 Unlocks the vehicle
X To unlock centrally: press the0036button.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
R the vehicle is locked again
R the anti-theft alarm system is armed again.
X To lock centrally: press the0037button.
The SmartKey centrally locks and unlocks the
doors, the glove box and the fuel filler flap.
The turn signals flash once when unlocking and three times when locking.
You can also set an audible signal to confirm
that the vehicle has been locked. The audible
signal can be activated and deactivated via the
multimedia system; see the Digital Operator's
Manual.
When the locator lighting is activated via the
multimedia system, it lights up when it is dark 66
SmartKeyOpening and closing

after the vehicle is unlocked with the SmartKey.
Information on activating and deactivating the
locator lighting can be found in the Digital Oper-
ator's Manual.
X To open the trunk lid: press and hold the
0054 button until the trunk lid opens. KEYLESS-GO
General notes Bear in mind that the engine can be started by
any of the vehicle occupants if there is a Smart-
Key in the vehicle (Y page 112).
Locking/unlocking centrally You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you only need carry the
SmartKey with you. You can combine the func-
tions of KEYLESS-GO with those of a conven-
tional SmartKey. Unlock the vehicle by using
KEYLESS-GO, for instance, and lock it using the 0037 button on the SmartKey.
The driver's door and the door at which the han- dle is used, must both be closed. The SmartKey
must be outside the vehicle. When locking or
unlocking with KEYLESS-GO, the distance
between the SmartKey and the corresponding
door handle must not be greater than 3 ft (1 m).
A check which periodically establishes a radio
connection between the vehicle and the Smart-
Key determines whether a valid SmartKey is in
the vehicle. This occurs, for example:
R when starting the engine
R while driving
R when using the remote trunk lid opening sen-
sor
R when the external door handles are touched
R during convenience closing X
To unlock the vehicle: touch the inner sur-
face of the door handle.
X To lock the vehicle: touch sensor surface 0043
or 0044.
Make sure that you do not touch the inner
surface of the door handle.
X Convenience closing feature: touch
recessed sensor surface 0044for an extended
period.
Further information on the convenience clos-
ing feature (Y page 78).
Deactivating and activating If you do not intend to use the vehicle for a lon-
ger period of time, you can deactivate KEYLESS-
GO. The SmartKey will then use very little power, thereby conserving battery power. For the pur-
poses of activation/deactivation, the vehicle
must not be nearby.
X To deactivate: press the0037button on the
SmartKey twice in rapid succession.
The indicator light on the SmartKey flashes
twice briefly then one long flash, then KEY-
LESS-GO is deactivated (Y page 69).
X To activate: press any button on the Smart-
Key.
or X Insert the SmartKey into the ignition lock.
KEYLESS-GO and all of its associated features
are available again. KEYLESS-GO start function
Bear in mind that the engine can be started by
any of the vehicle occupants if there is a Smart- Key in the vehicle (Y page 112). SmartKey
67Opening and closing Z

Changing the settings of the locking
system
You can change the settings of the locking sys-
tem. This means that only the driver's door, the
glove box and the fuel filler flap are unlocked
when the vehicle is unlocked. This is useful if you
frequently travel on your own.
X To change the setting: press and hold down
the 0036 and0037 buttons simultaneously
for approximately six seconds until the indi-
cator lamp flashes twice (Y page 69).
If the setting of the locking system is changed
within the signal range of the vehicle, pressing
the 0037 or0036 button:
R locks or
R unlocks the vehicle
The SmartKey now functions as follows:
X To unlock: press the0036button once.
X To unlock centrally: press the0036button
twice.
X To lock: press the 0037button.
The KEYLESS-GO functions can be changed as
follows:
X To unlock the driver's door: touch the inner
surface of the door handle on the driver's
door.
X To unlock centrally: touch the inner surface
of the front-passenger door handle.
X To lock centrally: touch the outer sensor
surface on one of the door handles.
Restoring factory settings:
X Press the 0036and0037 buttons simultane-
ously for approximately six seconds until the
indicator lamp flashes twice (Y page 69).Mechanical key
General notes If the vehicle can no longer be locked or
unlocked with the SmartKey or KEYLESS-GO,
use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm sys- tem will be triggered. Switch off the alarm
(Y page 64). If you unlock the vehicle using the mechanical
key, the fuel filler flap will not be unlocked auto-
matically.
X To unlock the fuel filler flap: insert the
SmartKey into the ignition lock.
Removing the mechanical key X
Push release catch 0043in the direction of the
arrow and at the same time remove mechan- ical key 0044from the SmartKey.
For further information about:
R unlocking the driver's door (Y page 73)
R locking the vehicle (Y page 73)
Inserting the mechanical key X
Push mechanical key 0044completely into the
SmartKey until it engages and release
catch 0043is back in its basic position. SmartKey battery
Important safety notes G
WARNING
Batteries contain toxic and corrosive substan- ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatal injury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention immediately. 68
SmartKeyOpening and closing