2017 MERCEDES-BENZ GLS check engine

Display messages
Possible causes/consequences and P Solutions
The yellow $ warning lamp lights up and th e red I (US A only)
or $ (Canada only) indicator lamp flashes .
It is no t possibl e to apply th e electric parking brak e manually.X
Shift th e transmission to position P .X
Visit a qualified specialist workshop .
' (USA
only)
M ( Canada
only)
Check Brake Fluid
Level There is no t enough brak e flui d in th e brak e flui d reservoir . In addition ,
th e ' (US A only) or M (Canada only) warning lamp lights up in
th e instrumen t cluste r and a warning tone sounds.
G WARNIN G
The braking effec t may be impaired.
There is a ris k of an accident.X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions. Do no t continu e drivin g
under any circumstances. X
Secur e th e vehicl e against rollin g away ( Y
page 159).X
Consult a qualified specialist workshop .X
Do no t add brak e fluid . This does no t correc t th e malfunction .
& Check Brake Pad Wea r The brak e pads/linings hav e reached their wear limit.
US A only: th e ' red brak e system warning lamp is lit while th e
engin e is running. X
Visit a qualified specialist workshop .
S Inoperative On e or mor e main features of th e mbrace system are malfunctioning .X
Visit a qualified specialist workshop .
Active Brake Assist
Functions Currently
Limite d See Opera‐
tor's Manual Active Brake Assis t wit h cross-traffic function is temporarily inopera-
tive.
Possibl e causes are: R
th e radar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti c radiation emitted by nearby TV or radi o station s or
other source s of electromagneti c radiationR
th e system is outside th e operating temperature rangeR
th e on-boar d voltag e is to o low.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
Active Brake Assis t wit h cross-traffic function or PRE ‑ S AF E ®
PLU S is
functional again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 159).X
Restart th e engine.250
Display messages
On-board computer and displays

Warning/
indicator
lamp Q Signal type
Possible causes/consequences and P Solutions
I$
Q I (USA only), $ (Canada only): the red indicator lamp for the electric
parking brake flashes or is lit and/or the yellow warning lamp for the electric
parking brake is lit. X
Observe the additional display messages in the multifunction display.
u
Q The red restraint system warning lamp is lit while the engine is running.
The restraint system is malfunctioning.
G WARNING
The air bags or Emergency Tensioning Devices may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury. X
Observe the additional display messages in the multifunction display. X
Drive on carefully. X
Contact a qualified specialist workshop and have the restraint system checked.
For further information about the restraint system, see ( Y
page 41).282
Warning and indicator lamps in the instrument cluster
On-board computer and displays

X
Make sure that the windshield wipers are
turned off. X
Pull release lever C on the hood.
The hood is released.
X
Reach into the gap, pull hood catch handle D
up and lift the hood.
If you lift the hood by approximately 15 in
(40 cm), the hood is opened and held open
automatically by the gas-filled strut.
Closing the hood X
Lower the hood and let it fall from a height of
approximately 8 in (20 cm). X
Check that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close it
with a little more force.
Radiator
Vehicles with a diesel engine: do not cover
the radiator, for example with a winter front or
bug cover. The readings of the on-board-diag-
nostic system may otherwise be inaccurate.
Some of these readings are required by law and
must be accurate at all times. Engine oil
Important safety notes
G WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and
touch only the components described in the
following.
G WARNING
If engine oil comes into contact with hot com-
ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Make sure that engine oil is not spilled next to
the filler neck. Let the engine cool down and
thoroughly clean the engine oil off the com-
ponents before starting the engine.
General notes Depending on your driving style, the vehicle
consumes up to 0.9 US qt (0.8 liters) of oil per
600 miles (1,000 km). The oil consumption may
be higher than this when the vehicle is new or if
you frequently drive at high engine speeds.
Depending on the engine, the oil dipstick may be
in a different location.
When checking the oil level: R
park the vehicle on a level surface. R
the engine should be switched off for approx-
imately five minutes if the engine is at normal
operating temperature. R
if the engine is not at normal operating tem-
perature, e.g. if the engine was only started
briefly, wait about 30 minutes before carrying
out the measurement.320
Engine compartment
Maintenance and care

Where possible, let the engine cool down and
touch only the components described in the
following.
G WARNING
The cooling system is pressurized, particularly
when the motor is warm. If you open the cap,
you could be scalded if hot coolant sprays out.
There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Slowly
open the cap to relieve pressure.
G WARNING
Windshield washer concentrate could ignite if
it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
Checking coolant level
X
Park the vehicle on a level surface.
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down. X
Turn the SmartKey to position 2 in the ignition
lock ( Y
page 138).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice ( Y
page 140).X
Check the coolant temperature gauge in the
multifunction display.
The coolant temperature must be below
158 ‡ (70 †). X
Turn the SmartKey to position 0 in the ignition
lock ( Y
page 138). X
On vehicles with KEYLESS-GO, press the
Start/Stop button ( Y
page 140).X
Press the Start/Stop button ( Y
page 140).X
Slowly turn cap C half a turn counter-clock-
wise and allow excess pressure to escape. X
Turn cap C further counter-clockwise and
remove it.
If the coolant is at the level of marker bar

X
If possible, bring the front wheels into the
straight-ahead position. X
Vehicles with the AIRMATIC package:
make sure that the normal vehicle level is
selected ( Y
page 188).X
Vehicles with the Off-Road Engineering
package: make sure that the normal level is
selected ( Y
page 182).X
Switch off the engine. X
Vehicles without KEYLESS-GO: remove the
SmartKey from the ignition lock. X
Vehicles with KEYLESS-GO: open the driv-
er's door.
The on-board electronics now have status 0 .
This is the same as the SmartKey having been
removed. X
Vehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock
( Y
page 138).X
Make sure that the passengers are not endan-
gered as they do so. Make sure that no one is
near the danger area while a wheel is being
changed. Anyone who is not directly assisting
in the wheel change should, for example,
stand behind the barrier. X
Get out of the vehicle. Pay attention to traffic
conditions when doing so. X
Close the driver's door. X
Unload heavy luggage.
i Only operate the tire inflation compressor
using a 12 V socket, even if the ignition is
turned off ( Y
page 306).
An emergency cut-out ensures that the on-
board voltage does not drop too low. If the on-
board voltage is too low, the power to the
sockets is automatically cut. This ensures
that there is sufficient power to start the
engine.
MOExtended tires (tires with run-flat
properties)
General notes
With MOExtended tires (tires with run flat char-
acteristics), you can continue to drive your vehi-
cle even if there is a total loss of pressure in one
or more tires. The affected tire must not show
any clearly visible damage.
You can recognize MOExtended tires by the
MOExtended marking which appears on the sidewall of the tire. You will find this marking
next to the tire size designation, the load-bear-
ing capacity and the speed index ( Y
page 361).
MOExtended tires may only be used in conjunc-
tion with an active tire pressure loss warning
system or with an active tire pressure monitor.
If a pressure loss warning message appears
in the multifunction display: R
observe the instructions in the display mes-
sages ( Y
page 268). R
check the tire for damage. R
if driving on, observe the following notes.
The driving distance possible in run-flat mode is
approximately 50 miles (80 km) when the vehi-
cle is partially laden and approximately 18 miles
(30 km) when the vehicle is fully laden.
In addition to the vehicle load, the driving dis-
tance possible depends upon: R
vehicle speed R
road condition R
outside temperature
The driving distance possible in run-flat mode
may be reduced by extreme driving conditions
or maneuvers, or it can be increased through a
moderate style of driving.
The driving distance possible in run-flat mode is
counted from the moment the tire pressure loss
warning appears in the multifunction display.
You must not exceed a maximum speed of
50 mph (80 km/h).
i When replacing one or all tires, please
observe the following specifications for your
vehicle's tires: R
size R
type and R
the "MOExtended" mark
If a tire has gone flat and cannot be replaced
with a MOExtended tire, a standard tire may
be used as a temporary measure. Make sure
that you use the proper size and type (sum-
mer or winter tire).
i Vehicles equipped with MOExtended tires
are not equipped with a TIREFIT kit at the fac-
tory. It is therefore recommended that you
additionally equip your vehicle with a TIR EFIT
kit if you mount tires that do not feature run-
flat properties, e.g. winter tires. A TIREFIT kit
may be obtained from a qualified specialist
workshop.332
Flat tire
Breakdown assistance

The vehicle will then use very little energy, thus
conserving battery power.
If the power supply has been interrupted, e.g. if
you reconnect the battery, you will have to: R
set the clock; see the Digital Operator's Man-
ual
On vehicles with a multimedia system and
navigation system, the clock is set automati-
cally. R
reset the function for folding the exterior mir-
rors in/out automatically, by folding the mir-
rors out once ( Y
page 108).
Charging the 12 V battery
G WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a
risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery.
G WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
G WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
! Only use battery chargers with a maximum
charging voltage of 14.8 V.
! Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment ( Y
page 338).X
Open the hood. X
Connect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure ( Y
page 338).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it
is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availability. Read the
battery charger's operating instructions before
charging the battery.
If, at low temperatures, the indicator lamps/
warning lamps in the instrument cluster do not
light up, it is highly likely that the discharged
battery has frozen. In this case you may neither
jump-start the vehicle nor charge the battery.
The service life of a thawed-out battery may be
shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have
the thawed-out battery checked at a qualified
specialist workshop.
Jump-starting
For the jump-starting procedure, use only the jump-starting connection point in the engine com-
partment, consisting of a positive terminal and a ground point.
G WARNING
Battery acid is caustic. There is a risk of injury.338
Jump-starting
Breakdown assistance

Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
G WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk
of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery.
G WARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion. R
Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts. R
Never place metal objects or tools on a battery. R
It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery. R
When jump-starting, make sure that the battery poles with identical polarity are connected. R
It is particularly important to observe the described order when connecting and disconnecting
the jumper cables. R
Never connect or disconnect the battery terminals while the engine is running.
G WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
! Vehicles with a gasoline engine: avoid repeated and lengthy starting attempts. Otherwise, the
catalytic converter could be damaged by non-combusted fuel.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the dis-
charged battery has frozen. In this case you may neither jump-start the vehicle nor charge the
battery. The service life of a thawed-out battery may be shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have the thawed-out battery checked at a qualified
specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a second battery using jumper cables.
Observe the following points: R
The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a second battery or a jump-starting device. R
Vehicles with a gasoline engine: only jump-start the vehicle when the engine and exhaust
system are cold. R
Do not start the engine if the battery is frozen. Let the battery thaw first. R
Only jump-start from batteries with a 12 V voltage rating. R
Only use jumper cables which have a sufficient cross-section and insulated terminal clamps. Jump-starting 339
Breakdo wn assis tance Z

be required earlier. Do not change the direction
of wheel rotation.
Clean the contact surfaces of the wheel and the
brake disc thoroughly every time a wheel is rota-
ted. Check the tire pressure and, if necessary,
restart the tire pressure loss warning system or
the tire pressure monitor ( Y
page 353).
Direction of rotation Tires with a specified direction of rotation have
additional benefits, e.g. if there is a risk of hydro-
planing. These advantages can only be gained if
the tires are installed corresponding to the
direction of rotation.
An arrow on the sidewall of the tire indicates its
correct direction of rotation.
Storing wheels Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the tires
from oil, grease, gasoline and diesel.
Mounting a wheel
Preparing the vehicle X
Vehicle with emergency spare wheel:
when mounting the emergency spare wheel in
the event of a flat tire, follow the additional
notes on vehicle preparation under "Flat tire"
( Y
page 331). X
Stop the vehicle on solid, non-slippery and
level ground. X
Apply the electric parking brake manually. X
Bring the front wheels into the straight-ahead
position. X
Vehicles with automatic transmission:
shift the automatic transmission to position
P . X
Vehicles with the AIRMATIC package:
make sure that the normal vehicle level is
selected ( Y
page 188).X
Vehicles with the Off-Road Engineering
package: make sure that the normal level is
selected ( Y
page 182).X
Switch off the engine. X
Vehicles without KEYLESS-GO: remove the
SmartKey from the ignition lock. X
Vehicles with KEYLESS-GO: open the driv-
er's door.
The on-board electronics now have status 0 .
This is the same as the SmartKey having been
removed. X
Vehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock
( Y
page 138). X
If included in the vehicle equipment, remove
the tire-change tool kit from the vehicle. X
Safeguard the vehicle against rolling away.
i Apart from certain country-specific varia-
tions, vehicles are not equipped with a tire-
change tool kit. For information on which
tools are required to perform a wheel change
on your vehicle, consult an authorized
Mercedes-Benz Center.
Necessary tire-changing tools can include, for
example: R
Jack R
Wheel chock R
Lug wrench
Securing the vehicle to prevent it from
rolling away
If your vehicle is equipped with a wheel chock, it
can be found in the tire-change tool kit
( Y
page 331).
The folding wheel chock is an additional safety
measure to prevent the vehicle from rolling
away, for example when changing a wheel. X
Fold both plates upwards C .X
Fold out lower plate D .X
Guide the lugs on the lower plate fully into the
openings in base plate