2018 MERCEDES-BENZ AMG GT ROADSTER warning light

If the tire pressures have been set to the lower
values for lighter loads and/or lower road
speeds, the pressures should be reset to the
higher values:
Rif you want to drive with an increased load
and/or
Rif you want to drive at higher road speeds
The tire pressures for increased loads and/or
higher road speeds, shown in the tire pressure
table, may have a negative effect on driving
comfort.
If the tire pressure is not set correctly, this can
lead to an excessive build-up of heat and a sud-
den loss of pressure.
For more information, contact a qualified spe-
cialist workshop.
Important notes on tire pressure
GWARNING
If the tire pressure drops repeatedly, the
wheel, valve or tire may be damaged. Tire
pressure that is too low may result in a tire
blow-out. There is a risk of an accident.
RCheck the tire for foreign objects.
RCheck whether the wheel is losing air or the valve is leaking.
If you are unable to rectify the damage, con-
tact a qualified specialist workshop.
GWARNING
If you fit unsuitable accessories onto tire
valves, the tire valves may be overloaded and
malfunction, which can cause tire pressure
loss. Due to their design, retrofitted tire pres- sure monitors keep the tire valve open. This
can also result in tire pressure loss. There is a
risk of an accident.
Only screw the standard valve cap or other
valve caps approved by Mercedes-Benz for
your vehicle onto the tire valve.
Use a suitable pressure gauge to check the tire
pressure. The outer appearance of a tire does
not permit any reliable conclusion about the tire pressure. On vehicles equipped with the elec-
tronic tire pressure monitor, the tire pressure
can be checked in the on-board computer.
The tire temperature and pressure increase
when the vehicle is in motion. This is dependent
on the driving speed and the load.
Therefore, you should only correct tire pres-
sures when the tires are cold.
The tires are cold:
Rif the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
Rif the vehicle has not been driven further than
1 mile (1.6 km)
The tire temperature changes depending on the
outside temperature, the vehicle speed and the
tire load. If the tire temperature changes by
18 ‡ (10 †), the tire pressure changes by
approximately 10 kPa (0.1 bar/1.5 psi). Take
this into account when checking the pressure of
warm tires. Only correct the tire pressure if it is
too low for the current operating conditions. If
you check the tire pressure when the tires are
warm, the resulting value will be higher than if
the tires were cold. This is normal. Do not
reduce the tire pressure to the value specified
for cold tires. The tire pressure would otherwise
be too low.
Observe the recommended tire pressures for
cold tires:
Ron the Tire and Loading Information placard
on the B-pillar on the driver's side
Rin the tire pressure table in the fuel filler flap
(Ypage 126).
Tire pressure265
Wheels and tires
Z

XIf the tire pressure is too low, increase the tire
pressure to the recommended value.
XIf the tire pressure is too high, release air. To
do so, press down the metal pin in the valve,
using the tip of a pen for example. Then check
the tire pressure again using the tire pressure
checker.
XScrew the valve cap onto the valve.
XRepeat these steps for the other tires.
Tire pressure monitor
General notes
If a tire pressure monitor is installed, the vehi-
cle's wheels have sensors that monitor the tire
pressures in all four tires. The tire pressure mon-
itor warns you if the pressure drops in one or
more of the tires. The tire pressure monitor only
functions if the corresponding sensors are
installed in all wheels.
Information on tire pressures is displayed in the
multifunction display. After a few minutes of
driving, the current tire pressure of each tire is
shown in the Service
menu of the multifunction
display; see illustration (example).
For information on the message display, refer to
the "Checking the tire pressure electronically"
section (
Ypage 268).
Important safety notes
GWARNING
Each tire, including the spare (if provided),
should be checked at least once every two
weeks when cold and inflated to the pressure recommended by the vehicle manufacturer
on the Tire and Loading Information placard
on the driver's door B-pillar or the tire pres-
sure label on the inside of the fuel filler flap. Ifyour vehicle has tires of a different size than
the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label, you should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your tires
are significantly underinflated. Accordingly,
when the low tire pressure telltale lights up,
you should stop and check your tires as soon
as possible, and inflate them to the proper
pressure. Driving on a significantly underin-
flated tire causes the tire to overheat and can
lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle's
handling and stopping ability. Please note that
the TPMS is not a substitute for proper tire
maintenance, and it is the driver's responsi-
bility to maintain correct tire pressure, even ifunderinflation has not reached the level to
trigger illumination of the TPMS low tire pres-
sure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined with
the low tire pressure telltale. When the sys-
tem detects a malfunction, the warning lamp
will flash for approximately a minute and thenremain continuously illuminated. This
sequence will be repeated every time the vehi-
cle is started as long as the malfunction
exists. When the malfunction indicator is illu-
minated, the system may not be able to detect
or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of
reasons, including the installation of incom-
patible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly. Always check the
TPMS malfunction telltale a
fter replacing one
or more tires or wheels on your vehicle to
Tire pressure267
Wheels and tires
Z

ensure that the replacement or alternate Tires
and wheels allow the TPMS to continue to
function properly.
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation
(
Ypage 264). Note that the correct tire pressure
for the current operating situation must first be
taught-in to the tire pressure monitor. If a sub-
stantial loss of pressure occurs, the warning
threshold for the warning message is aligned to
the taught-in reference values. Restart the tire
pressure monitor after adjusting the pressure of
the cold tires (
Ypage 269). The current pres-
sures are saved as new reference values. As a
result, a warning message will appear if the tire pressure drops significantly.
The tire pressure monitor does not warn you of
an incorrectly set tire pressure. Observe the
notes on the recommended tire pressure
(
Ypage 264).
The tire pressure monitor is not able to warn you
of a sudden loss of pressure, e.g. if the tire is
penetrated by a foreign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.
The tire pressure monitor has a yellow warning
lamp in the instrument cluster for indicating
pressure loss or a malfunction. Whether the
warning lamp flashes or lights up indicates
whether a tire pressure is too low or the tire
pressure monitor is malfunctioning:
Rif the warning lamp is lit continuously, the tire
pressure on one or more tires is significantly
too low. The tire pressure monitor is not mal-
functioning.
Rif the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
In addition to the warning lamp, a message
appears in the multifunction display. Observe
the information on display messages
(
Ypage 191).
It may take up to ten minutes for a malfunction
of the tire pressure monitor to be indicated. A
malfunction will be indicated by the tire pres-
sure warning lamp flashin
g for approximately
one minute and then remaining lit. When the
malfunction has been rectified, the tire pressure
warning lamp goes out after a few minutes of
driving. The tire pressure values indicated by the on-
board computer may differ from those meas-
ured at a gas station with a pressure gage. The
tire pressures shown by the on-board computer
refer to those measured at sea level. At high
altitudes, the tire pressure values indicated by a pressure gage are higher than those shown by
the on-board computer. In this case, do not
reduce the tire pressures.
The operation of the tire pressure monitor can
be affected by interference from radio transmit-
ting equipment (e.g. radio headphones, two-way
radios) that may be being operated in or near the vehicle.
Checking the tire pressure electroni-
cally
XSwitch on the ignition (Ypage 111).
XPress òon the steering wheel to call up
the list of menus.
XPress 9or: on the steering wheel to
select the Servicemenu.
XPressa.
XPress9or: to select Tire Pres‐sure.
XPressa.
The current tire pressure of each tire is shown
in the multifunction display.
If the vehicle was parked for longer than
20 minutes, the Tire pressure will be
displayed after driving a few minutesmessage appears.
After a teach-in process, the tire pressure mon-
itor automatically detects new wheels or new
sensors. As long as a clear allocation of the tire
pressure value to the individual wheels is not
possible, theTire
PressureMonitorActivemessage is shown instead of the tire pressure
display. The tire pressures are already being
monitored.
Tire pressure monitor warning mes-
sages
If the tire pressure monitor detects a pressure
loss in one or more tires, a warning message is
shown in the multifunction display. The yellow
tire pressure warning lamp then lights up.
RIf thePlease Correct Tire Pressuremessage appears in the multifunction display,
the tire pressure in at least one tire is too low.
268Tire pressure
Wheels and tires

Tire labeling
Overview
:Uniform Tire Quality Grading Standard
(Ypage 277)
;DOT, Tire Identification Number
(Ypage 276)
=Maximum tire load (Ypage 276)
?Maximum tire pressure (Ypage 266)
AManufacturer
BTire material (Ypage 277)
CTire size designation, load-bearing capacity
and speed rating (Ypage 274)
DLoad index (Ypage 276)
ETire name
The markings described above are on the tire in
addition to the tire name (sales designation) and
the manufacturer's name.
iTire data is vehicle-specific and may deviate
from the data in the example.
Tire size designation, load-bearing
capacity and speed rating
GWARNING
Exceeding the stated tire load-bearing capa-
city and the approved maximum speed could
lead to tire damage or the tire bursting. There is a risk of accident.
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
tire load rating and speed rating required for
your vehicle.
:Tire width
;Nominal aspect ratio in %
=Tire code
?Rim diameter
ALoad bearing index
BSpeed rating
General: depending on the manufacturer's
standards, the size imprinted in the tire wall may
not contain any letters or may contain one letter
that precedes the size description.
If there is no letter preceding the size descrip-
tion (as shown above): these are passenger
vehicle tires according to European manufac-
turing standards.
If "P" precedes the size description: these are
passenger vehicle tires according to U.S. man-
ufacturing standards.
If "LT" precedes the size description: these are
light truck tires according to U.S. manufacturing
standards.
If "T" precedes the size description: compact
emergency wheels with high tire pressure that
are only designed for temporary use in an emer-
gency.
Tire width: tire width:shows the nominal tire
width in millimeters.
Height-width ratio: aspect ratio;is the size
ratio between the tire height and tire width and
is shown in percent. The aspect ratio is calcula-
ted by dividing the tire width by the tire height.
Tire code: tire code=specifies the tire type.
"R" represents radial tires; "D" represents diag-
onal tires
; "B" represents diagonal radial tires.
Optionally, tires with a maximum design speed
of over 149 mph (240 km/h) may have "ZR" in
274All about wheels an d tires
Wheels and tires