2001 MERCEDES-BENZ C320 key battery

156 Automatic climate control
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Residual engine heat utilization
With the engine switched off, it is possible to continue
to heat or ventilate the interior for a short while. Air
volume and distribution are controlled automatically.
To select:
Turn the electronic key in starter switch to position 1
or 0 or remove it altogether.
Press button T. The indicator lamp in the button
illuminates.
This function selection will not activate if the battery
level is insufficient. The function switches off automatically:
•if the electronic key in starter switch is turned to
position 2,
•after approximately 30 minutes,
•if the battery voltage drops.

157 Automatic climate control
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Rear window defroster
Turn the electronic key in starter switch to position 2.
To select:
Press the F button in the control panel of the
automatic air conditioner. The indicator lamp in the
button illuminates.
To c a nc el:
Press the F button in the control panel of the
automatic air conditioner. The indicator lamp in the
button goes out.
Note:
Heavy accumulation of snow and ice should be removed
before activating the defroster. The rear wind ow de fr oster us es a large amount of power.
To keep the battery drain to a minimum, turn off the
defroster as soon as the rear window is clear.
The defroster is automatically turned off after
approximately 6–17 minutes of operation depending on
the outside temperature and vehicle speed.
If several power consumers are turned on
simultaneously, or the battery is only partially charged,
it is possible that the defroster will automatically turn
itself off. When this happens, the indicator lamp inside
the switch starts blinking.
As soon as the battery has sufficient voltage, the
defroster automatically turns itself back on.

163 Audio system
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Button and soft key operation
In these instructions, the alpha-numeric keypad (right
side of radio face) and the function buttons (left side of
the radio face) are referred to as “buttons” and the four
keys under the display are referred to as “soft keys”
Note:
Do not press directly on the radio display face.Operation
Switching on and off
Press the control knob .
The system is switched off when the electronic main key
in the starter switch is turned to position 0 or removed.
The radi o is swi tched on again when the electron ic main
key in the starter switch is turned to position 1 or 2.
Note:
The system can also be switched on separately with the
electronic main key removed, but will switch itself off
automatically after half an hour to conserve vehicle
battery power.

188 Interior equipment
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Opening or closing the sliding / pop-up roof
automatically
Move the switch past resistance point in the direction
required and release.
The sliding / pop-up roof opens or closes completely.
Stopping the sliding / pop-up roof:
Move the switch in any direction.
If the movement of the sliding / pop-up roof is blocked
during the closing procedure, the roof will stop and
reopen slightly.With the roof closed or tilted open, a screen can be slid
into the roof opening to guard against sun rays. When
sliding the roof open, the screen will also retract.
Notes:
The sliding / pop-up roof can also be opened and closed
using the summer opening / convenience feature, see
page 29.
To avoid damaging the seals, do not transport any
objects with sharp edges which can stick out of the
sliding / pop-up roof.
The sliding/pop-up roof can be opened or closed
manually should an electrical malfunction occur, see
page 335.
Synchronizing the sliding / pop-up roof
The sliding / pop-up roof must be resynchronized if the
power supply has been interrupted (battery
disconnected or low), the sliding / pop-up roof has been
closed manually or the sliding / pop-up roof does not
open smoothly or malfunctions.
•Press the switch in the “raise” (3) direction, wait
until the sliding / pop-up roof is fully raised at rear
and hold the switch for approximately 1 second.
Wa r n i n g !
When closing the sliding / pop-up roof, be sure that
there is no danger of anyone being harmed by the
closing procedure.When leaving the vehicle, always remove the
electronic key from starter switch, and lock your
vehicle. Do not leave children unattended in the
vehicle, or with access to an unlocked vehicle.
Unsupervised use of vehicle equipment can cause
serious personal injury.

190 Interior equipment
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Notes:
The time delay for the interior light to switch off after
the electronic key is removed from the starter switch
can be adjusted in the “Individual settings” –
“LIGHTING”. See page 117.
To prevent the vehicle battery from being discharged
with doors open, all interior lamps switch off after
approximately 5 minutes.
An interior lamp switched on manually does not go out
automatically. Before leaving the vehicle, make sure that
all interior lamps are switched off.Door entry lamps
The appropriate entry lamp switches on if a door is
opened in darkness and if the interior lighting is
switched to automatic function.
The entry lamp switches off automatically when the
door is closed.

220 Tele Aid
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Tele Aid
Important!
The initial activation of the Tele Aid system may only be
performed by completing the subscriber agreement and
placing an acquaintance call using the “SOS” button.
Failure to complete either of these steps will result in a
system that is not activated.
If you have any questions regarding activation, please
call the Response Center at 1-800-756-9018 (in the USA)
or 1-888-923-8367 (in Canada).
(Te l ematic Alarm Identification on Demand)
The Tele Aid system consists of three types of response;
automatic and manual emergency, roadside assistance
and information.
The Tele Aid system is always operational, providing
that the vehicle’s battery is charged and properly
connected. To activate, press the “SOS” button, the
Roadside Assistance button or the Information
button¡, depending on the type of response
required.System self-check
Initially, after turning the electronic key in starter
switch to position 2, malfunctions are detected and
indicated (the indicator lamps in the “SOS” button, the
Roadside Assistance button and the Information
button¡ stay on longer than 5 seconds or do not
come on).
If a malfunction is indicated as outlined above, have the
system checked at the nearest Mercedes-Benz Center as
soon as possible.
Important!
Always make sure that the indicator lamp in the
“SOS” button remains illuminated for approximately
5 seconds during the system self-check after turning
electronic key in starter switch to position 2.
Emergency calls
An emergency call is initiated automatically following
an accident in which the Emergency Tensioning
Retractors (ETR’s) or airbags deploy. An emergency call
can also be initiated manually by opening the cover next
to the inside rear view mirror labeled “SOS”, then

231 Starter switch
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Important!
If the electronic key is left in the starter switch
position 0 for a extended period of time, it can no longer
be turn ed in t he lock . In t his cas e, rem ove electron ic key
from starter switch and reinsert.
Caution!
To prevent accelerated battery discharge and a possible
dead battery, always remove the electronic key from the
starter switch. Do not leave the electronic key in starter
switch position 0.Notes:
A warning sounds when the driver’s door is opened
with the electronic key is in starter switch position 1
or 0.
With the engine at idle speed, the charging rate of the
alternator (output) is limited.
It is therefore recommended that you turn off
unnecessary electrical consumers while driving in stop-
and-go traffic. This precaution helps to avoid draining of
the battery.
Unnecessary strain on the battery and charging system
may be minimized by turning off the following power
consumers, for example:
Heated seats, rear window defroster. In addition, the
automatic climate air volume control should be set to
the lowest position.

261 Driving systems
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Notes:
The yellow ESP warning lampv in the speedometer
dial comes on with the electronic key in starter switch
position 2. It should go out with the engine running.
If the ESP warning message is displayed, a malfunction
has been detected in the system. Pressing the
accelerator pedal will require greater effort. Only partial
engine output will be available.
Have the ESP checked at your authorized
Mercedes-Benz Center as soon as possible.
For ESP warning message, see page 273.
With the ABS malfunctioning, the ESP is also switched
off.
Driving the vehicle with varied size tires will cause the
wheels to rotate at different speeds, therefore the ESP
may activate (yellow ESP warning lamp in speedometer
d ial com es on ). For t his reas on, all wheels, in cludin g t he
spare wheel, must have the same tire size. When testing the parking brake on a brake test
dynamometer, the engine must be shut off. Otherwise,
the ESP will immediately be engaged and will apply the
rear wheel brakes.
In winter operation, the maximum effectiveness of the
ESP is only achieved with Mercedes-Benz recommended
M+S rated radial-ply tires and / or snow chains.
Synchronizing ESP
If the power supply was interrupted (battery
disconnected or empty), the ESP warning message may
be displayed with the engine running.
Turn steering wheel completely to the left and then to
the right. The ESP warning message should go out.