2003 MERCEDES-BENZ S CLASS battery

291 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
-
The yellow ABS malfunction indi-
cator lamp comes on while driv-
ing.
The ABS has detected a malfunction and has
switched off. The BAS and the ESP are also
switched off (see messages in display).
The brake system is still functioning normally
but without the ABS available.
If the ABS control unit is malfunctioning, oth-
er systems such as Parktronic*, Distronic*,
the navigation system, and the automatic
transmission can also malfunction.

Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.

Have the system checked at an autho-
rized Mercedes-Benz Center as soon
as possible.
Failure to follow these instructions in-
creases the risk of an accident.
The charging voltage has fallen below
10 volts and the ABS has switched off.

When the voltage is above this value
again, the ABS is operational again.

If necessary, have the generator and
battery checked.
l
The red Distronic warning lamp
lights up while driving.
You are too close to the vehicle in front of you
to maintain selected speed.

Apply the brakes immediately to in-
crease the following distance.
l
The red Distronic warning lamp
comes on while driving and you
hear a warning sound.


You are gaining too rapidly on the vehicle
ahead of you.


The distance warning system has recog-
nized a stationary obstacle on your prob-
able line of travel.

Apply the brakes immediately.

Carefully observe the traffic situation.
You may need to brake or maneuver
to avoid hitting an obstacle.

301 Practical hints
What to do if …?
Display
Possible cause
Suggested solution
#
BATTERY/ALTERNATOR
VISIT WORKSHOP!
The battery was charged with a battery
charger or jump started.

Have the battery checked at a ser-
vice station.
The battery is no longer charging.
Possible causes:

Alternator malfunctioning


Broken poly-V-belt
Do not forget that the brake system re-
quires electrical energy and may be operat-
ing with restricted capability. Considerably
greater brake pedal force is required and
the stopping distance is longer.

Stop immediately and check the
poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise
the engine will overheat due to an in-
operative water pump which may re-
sult in damage to the engine. Notify
an authorized Mercedes-Benz
Center.
If it is intact:

Drive immediately to the nearest au-
thorized Mercedes-Benz Center. Ad-
just driving to be consistent with
reduced braking responsiveness.

303 Practical hints
What to do if …?
Display
Possible cause
Suggested solution
F
CHIP CARD
CHECK BATTERY
KEYLESS-GO*card batteries are dis-
charged.

Change the batteries (
page 328).
CHIP CARD
NOT RECOGNIZED!
KEYLESS-GO*card is not recognized while
the engine is running because

the card is not in the vehicle


there is strong radio-frequency interfer-
ence

Stop the vehicle as soon as it is safe
to do so.

Search for the card.
Otherwise the vehicle cannot be central-
ly locked nor can the engine be started
again after it has been stopped.
KEYLESS-GO*card is momentarily not rec-
ognized.

Change the position of the card in
the vehicle.

Operate the vehicle with the
SmartKey in the ignition if necessary.
CHIP CARD
DETECTED IN VEHICLE
KEYLESS-GO*card left in the vehicle was
recognized while locking the vehicle from
the outside.

Take the card out of the vehicle.
CHIP CARD
VISIT WORKSHOP!
The KEYLESS-GO* system is malfunction-
ing.

Visit an authorized Mercedes-Benz
Center as soon as possible.

320 Practical hintsWhat to do if …?Display
Possible cause
Suggested solution
H
TIRE PRES., LR
CAUTION, TIRE DEFECT!
The left rear tire is rapidly deflating.

Carefully bring the vehicle to a halt, avoid-
ing abrupt steering and braking maneu-
vers.

Change the wheel (
page 339).
TIRE PRES., LR
CHECK TIRES!
The left rear tire pressure is low.

Carefully bring the vehicle to a halt.

Check the tire pressure.

Change the wheel (
page 339).
Warning!
G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle.
You may lose control of the vehicle. Contin-
ued driving with a flat tire will cause exces-
sive heat build-up and possibly a fire.
Display
Possible cause
Suggested solution
L
TELE AID
VISIT WORKSHOP!
One or more main functions of the Tele Aid
system are malfunctioning.

Have the Tele Aid system checked by
an authorized Mercedes-Benz Cen-
ter.
TELE AID BATTERY
VISIT WORKSHOP!
The emergency power battery for the Tele
Aid system is malfunctioning. If the vehicle
battery is also discharged, Tele Aid will not
be operational.

Have the Tele Aid system checked by
an authorized Mercedes-Benz Cen-
ter.

328 Practical hintsUnlocking/locking in an emergencyChanging batteries
If the batteries in the SmartKey or the
KEYLESS-GO* card are discharged, the ve-
hicle can no longer be locked or unlocked.
It is recommended to have the batteries re-
placed at an authorized 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
1Mechanical key
2Battery compartment
Replacement batteries: Lithium, type
CR 2025 or equivalent.

Remove mechanical key1.

Insert the mechanical key in side open-
ing and push gray slide.
The battery compartment is unlatched.

Pull the battery compartment out of the
SmartKey housing in direction of ar-
row.

Remove the batteries.
Warning!
G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
iWhen changing batteries, always re-
place both batteries.
The required replacement batteries are
available at any authorized
Mercedes-Benz Center.

329 Practical hints
Unlocking/locking in an emergency
3Battery
4Contact spring
Using a lint-free cloth, insert new bat-
teries under the contact spring with the
plus (+) side facing up.

Return battery compartment into hous-
ing until it locks into place.KEYLESS-GO* card
1Battery cover
Replacement batteries: Lithium, type
CR 2025 or equivalent.

Pry open cover 1 (e.g. by using a nar-
row blade screwdriver).

Remove the batteries.

Install new batteries as indicated by
the “+” and “-” markings in the
KEYLESS-GO card.

Replace battery cover 1.
Fuel filler flap
In an emergency, the fuel filler flap can be
opened from the trunk. The release lever is
located on the right-hand side in the trunk.
1Release knob
Open the trunk with the mechanical
key (
page 326).

Remove the trim inside the trunk on the
right-hand side.

Pull release lever1 in the direction of
the arrow.
The fuel filler flap can be opened.

344 Practical hintsBattery
Battery
The battery is located on the right side of
the trunk under the battery cover.
1Battery cover 
Pull on the outer, right-hand side of
cover1 and remove it in the direction
of the arrow.
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.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the SmartKey is in the starter switch.
Otherwise the alternator and other
electronic components could be se-
verely damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Refer to Service Booklet for mainte-
nance intervals or contact your autho-
rized Mercedes-Benz Center for further
information.Warning!
G
With a disconnected battery

you will no longer be able to turn the
SmartKey in the starter switch and
pressing the KEYLESS-GO* start/stop
button (if so equipped) on the selector
lever will have no effect


the selector lever will remain locked in
positionP

345 Practical hints
Battery
2Positive terminal
3Negative terminalDisconnecting the battery
Turn off all electrical consumers.

Open the trunk lid (
page 95).

Remove the battery cover1.

Detach negative terminal3 of battery
with 10 mm open-end wrench from the
vehicle tool kit.

Remove cover from the positive
terminal2.

Detach the positive terminal of the bat-
tery with the 10 mm open-end wrench.
Removing the battery
Remove the screw securing the bat-
tery.

Remove the battery support and
bracket.

Take out the battery.
Charging and reinstalling battery
Charge battery in accordance with the
instructions of the battery charger
manufacturer.

Reinstall the charged battery. Follow
the previously described steps in re-
verse order.
Reconnecting the battery
Turn off all electrical consumers.

Connect the positive lead and fasten its
cover2.

Connect negative lead3.Warning!
G
Never charge a battery while still installed in
the vehicle. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.!Never invert the terminal connections.!The battery, its filler caps and the vent
tube must always be securely installed
when the vehicle is in operation.