Page 209 of 489

208 Controls in detail
Retractable hardtop
Unlocked status noticed when stopped
Switch on the ignition (page 40).
To lock the retractable hardtop in its
fully closed position, press retractable
hardtop switch forward (
page 205).
or:
To lock the retractable hardtop in its
fully opened position, pull up on the re-
tractable hardtop switch (
page 205).Unlocked status noticed while drivingStop the vehicle in a safe location or as
soon as it is safe to do so.
Leave the ignition switched on.
To lock the retractable hardtop in its
fully closed position, press retractable
hardtop switch forward (
page 205).
or:
To lock the retractable hardtop in its
fully opened position, pull up on the re-
tractable hardtop switch (
page 205).Problems when operating the
retractable hardtop
Several conditions may cause the retract-
able hardtop to not open, close, or lock
properly:
The luggage cover in the trunk is not
closed.
Close the luggage cover in the
trunk.
The trunk lid is open.
Close the trunk lid.
The battery voltage is too low.
Start engine and let run while open-
ing/closing the retractable hard-
top.
Warning!G
Stop the vehicle in a safe location or as soon
as it is safe to do so and lock the hardtop be-
fore continuing to drive. You could other-
wise endanger yourself and others.
Page 378 of 489

377 Practical hints
What to do if …
Left displayRight displayPossible cause/consequencePossible solution
# Battery/
Alternator
Stop CarThe battery is malfunctioning.
The electro-hydraulic brake system
requires electrical energy and
therefore has only limited opera-
tion. Considerably greater brake
pedal force is required and the stop-
ping distance is increased.Stop the vehicle in a safe location.
Adjust driving to be consistent with reduced
braking responsiveness.
Contact an authorized Mercedes-Benz
Center.
USA only:
;
Canada only:
3
Reduced
Brake Effect
Start EngineThe battery has insufficient voltage
and cannot supply sufficient power
to the electro-hydraulic brake sys-
tem.Start the engine.
The message disappears when sufficient
voltage is available.
Warning!G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and lead to death. Do not
run the engine in confined areas (such as a
garage) which are not properly ventilated.
Page 392 of 489

391 Practical hints
What to do if …
Left displayRight displayPossible cause/consequencePossible solution
FKey
Not DetectedThe SmartKey with KEYLESS-GO* is
not recognized while the engine is
running because:
The SmartKey with
KEYLESS-GO* is not in the vehi-
cle.
There is strong radio-frequency
interference.
Stop the vehicle in a safe location or as soon
as it is safe to do so.
Search for the SmartKey with KEYLESS-GO*.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started again af-
ter the engine is stopped.
Operate the vehicle with the SmartKey with
KEYLESS-GO* in the starter switch.
Key
Not DetectedThe SmartKey with KEYLESS-GO* is
not recognized when attempting to
start the engine with the
KEYLESS-GO start/stop button* on
the gear selector lever because:
The SmartKey with
KEYLESS-GO* is not in the vehi-
cle.
The battery in the SmartKey
with KEYLESS-GO* is not insert-
ed properly or completely dis-
charged.
Change the position of the SmartKey with
KEYLESS-GO* in the vehicle.
Make sure the batteries in the SmartKey with
KEYLESS-GO* are properly inserted
(
page 407) and are not discharged
(
page 113).
Start the engine with the SmartKey with
KEYLESS-GO* in the starter switch if
necessary.
Page 432 of 489

431 Practical hints
Batteries
Charge batteries in accordance with
the instructions of the battery charger
manufacturer.
Reinstall the charged batteries. Follow
the previously described steps in re-
verse order.
Reconnecting the batteries
Turn off all electrical consumers.
Install starter battery in the designated
location in the engine compartment.
Install consumer battery in the desig-
nated location in the trunk.
Attach supports and brackets.
Tighten support and bracket screws.
Connect positive lead 4 (page 427)
of the consumer battery and positive
lead 1 (
page 427) of the starter bat-
tery and fasten covers.
Connect negative lead 2
(
page 427) of the starter battery.
Connect negative lead 5
(
page 427) of the consumer battery.
Reinstall the trunk floor.
Close trunk luggage cover
(
page 211).
!Always connect the batteries in the order
described below. Otherwise the vehicle’s elec-
tronics can be damaged.
!Never invert the terminal connections!
iThe following procedures must be carried
out following any interruption of battery power
(e.g. due to reconnection):
Synchronize the ESP® (page 367).
Synchronize side windows (page 203).