Page 580 of 705

579 Practical hints
What to do if …?
Display
Possible cause/consequence
Possible solution
Parking brake
See Oper. Manual
When you engage or release the electric
parking brake, the red indicator lamp for
the electric parking brake flashes for
approx.10 seconds. Afterward, it goes out
or lights up continuously. The yellow warn-
ing lamp for the electric parking brake lights
up.
The electric parking brake is malfunctioning
or overheated for example due to over- or
undervoltage.
Carefully drive off (
page 364).
Visit an authorized Mercedes-Benz Center as
soon as possible.
In the event of overvoltage or undervoltage:
Remove the cause of the overvoltage or und-
ervoltage, e.g. charge the battery or restart
the engine.
Switch ignition off and back on again, and en-
gage or release electric parking brake
(page 364).
If the electric parking brake still cannot be re-
leased:
Release electric parking brake mechanically
(page 616).
Visit an authorized Mercedes-Benz Center as
soon as possible.
(Continued on next page)
(USA only)(Canada only)
Page 587 of 705
586 Practical hintsWhat to do if …?Display
Possible cause/consequence
Possible solution
Vehicle rising
Please wait a moment
The vehicle level is too low while at a stand-
still. The vehicle will be raised.
Do not drive off.
Wait until the message disappears from the
multifunction display.
You may then drive off.
The battery is no longer charging.
Possible causes:
alternator malfunctioning
broken poly-V-belt
Stop immediately and check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the en-
gine will overheat due to an inoperative water
pump which may result in damage to the en-
gine. Notify an authorized Mercedes-Benz
Center.
If it is intact:
Drive immediately to the nearest authorized
Mercedes-Benz Center.
Page 616 of 705

615 Practical hints
Unlocking/locking in an emergency
Unlocking the trunk
A minimum height clearance of 5.9 ft.
(1.80 m) is required to open the trunk lid.
1Trunk lid lock
Insert the mechanical key into the
trunk lid lock1 until it stops.
Turn mechanical key all the way to the
left.
The trunk opens.
Turn the mechanical key back and re-
move it from the trunk lid lock.
Locking the vehicle
If you cannot lock the vehicle with the
SmartKey or KEYLESS-GO*, do the follow-
ing:
Close the front passenger door, the
rear right door and the trunk.
Open the driver’s door and the rear left
door.
Press the central locking switch on the
driver’s door (
page 314).
The locking knobs of the front passen-
ger door and the rear doors move
down.
If the vehicle battery is disconnected or
drained:
Press down the locking knobs of
the front passenger door and the
rear doors manually.
Exit the vehicle.
Close the driver’s door.
Enter the vehicle through the rear left
door.
Press down the locking knob of the
driver’s door.
Exit the vehicle.
Close the rear left door.
The vehicle is locked.
!
The trunk lid swings open upwards automat-
ically. Always make sure that there is sufficient
overhead clearance.
!
To prevent inadvertent lockout, make sure
to have the SmartKey or SmartKey with KEY-
LESS-GO* with you before proceeding with the
next step. The next step will lock the vehicle.
Page 620 of 705

619 Practical hints
Replacing SmartKey batteries
Replacing SmartKey batteries
If the batteries in the SmartKey or the
SmartKey with KEYLESS-GO* are dis-
charged, the vehicle can no longer be
locked or unlocked. It is recommended to
have the batteries replaced at an autho-
rized Mercedes-Benz Center.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.SmartKey/SmartKey with
KEYLESS-GO*
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key out of the
SmartKey or the SmartKey with
KEYLESS-GO* (
page 614).
1Mechanical key
2Battery compartment
Insert mechanical key 1 into opening.
Press mechanical key 1 in direction of
arrow.
The battery compartment is unlatched.
Warning!
G
Batteries contain poisonous and corrosive
substances. Therefore keep the batteries
out of reach of children.
If a battery is swallowed, seek medical help
immediately.
i
When inserting the batteries, make sure
they are clean and free of lint.
i
When changing batteries, always replace
both batteries.
The required replacement batteries are available
at any authorized Mercedes-Benz Center.
Page 621 of 705
620 Practical hintsReplacing SmartKey batteries
Pull battery compartment 2 out of the
housing.
3Batteries
4Contact springs
Pull out batteries3.
Using a line-free cloth, insert new bat-
teries 3 under contact springs 4 with
the positive terminal (+) side facing up.
Return battery compartment 2
(page 619) into housing until it locks
into place.
Slide the mechanical key back into the
SmartKey/SmartKey with
KEYLESS-GO*.
Check the operation of the SmartKey/
KEYLESS-GO*.
Page 635 of 705

634 Practical hintsBatteriesYour vehicle is equipped with two batter-
ies:
The starter battery (located in the en-
gine compartment)
The battery for electrical consumers
(located in the trunk)
The batteries should always be sufficiently
charged in order to achieve its rated ser-
vice life. Refer to Maintenance Booklet for
battery maintenance intervals.
If you use your vehicle mostly for short-dis-
tance trips, you will need to have the bat-
tery charge checked more frequently.
When replacing the batteries, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Center about
steps you need to observe.Batteries contain materials that can harm
the environment if disposed of improperly.
Large 12-volt storage batteries contain
lead. Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
!
Do not tow-start the vehicle.
Warning!
G
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
faceguard.
Wear eye protection.
Rinse any acid spills immediate-
ly with clear water. Contact a
physician if necessary.
Keep children away.
Follow the instructions in this
Operator’s Manual.
Page 636 of 705

635 Practical hints
Batteries
!
The consumer battery located in the trunk is
a valve-r
egulated l
ead a
cid (VRLA) battery, also
referred to as “fleece” battery. Such batteries do
not require topping-up of the electrolyte level.
VRLA batteries therefore do not have cell caps
and the battery cover is non-removable. Do not
attempt to open the consumer battery as other-
wise the battery will be damaged.
Even though VRLA batteries do not require top-
ping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the bat-
tery condition must be checked periodically by
performing a battery conductance test. Refer to
Maintenance Booklet for battery condition test-
ing intervals.
As with any other battery, disconnect the con-
sumer battery if you do not intend to operate
your vehicle for an extended period of time to
prevent battery discharge or connect an acces-
sory battery charge unit expressly approved by
Mercedes-Benz for your vehicle model to main-
tain the battery charge. Contact an authorized
Mercedes-Benz Center for further information.
!
The factory-equipped VRLA battery is
leak-proofed. Only use a battery as replacement
that has the same security features and is of
identical size, voltage, and capacity as the facto-
ry-equipped battery.
The battery, the battery ventilation and the later-
al plug must always be securely installed when
the vehicle is in operation.
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.
Take care that you do not become statically
charged, e.g. by wearing synthetic clothing
or rubbing against textiles. For this reason,
you also should not pull or push the battery
over carpets or other synthetic materials.
Never touch the battery first. First touch the
outside body of the vehicle in order to re-
lease any possible electrostatic charges.
Page 637 of 705

636 Practical hintsBatteries
Starter battery (example illustration from
S550)1Negative terminal
2Positive terminal
Disconnecting starter battery
Do not rub the battery with rags or cloths.
The battery could explode if touched due to
electrostatic charge or due to spark forma-
tion.!
Switch off the engine and switch off the ve-
hicle’s internal electrical functions (
page 637)
before you disconnect or remove the battery’s
terminal clamps. You could otherwise destroy
electronic assemblies such as the generator.
Have the battery checked regularly by an autho-
rized Mercedes-Benz Center. Refer to Mainte-
nance Booklet for maintenance intervals or
contact an authorized Mercedes-Benz Center for
further information.
!
Do not connect any consumers directly to
the starter battery. The starter battery will other-
wise be discharged.
i
Only replace a discharged battery with a bat-
tery recommended by Mercedes-Benz. The con-
sumer battery is installed in the trunk in such a
way that it is safeguarded as much as possible
against mechanical destruction in the event of
an accident.
i
Remove SmartKey from starter switch (vehi-
cles with KEYLESS-GO*: Make sure the vehicle’s
on-board electronics have status 0)
(
page 315) when you turn off the engine and
no longer require any electrical consumers. The
vehicle then uses very little power and the con-
sumer battery is spared.
i
If the consumer battery is discharged, you
must use the mechanical key to unlock the vehi-
cle (page 614). Since the vehicle has a sepa-
rate starter battery, however, you can still start
the vehicle.
!
Always disconnect the starter battery in the
order described below. You could otherwise
damage the vehicle’s electronics.
!
Switch off the vehicle’s internal electrical
functions before disconnecting the starter bat-
tery. If the vehicle is stationary for more than one
hour with the SmartKey removed, you do not
need to switch off the vehicle’s internal electrical
functions.