2004 MERCEDES-BENZ CL500 brake sensor

198 Controls in detailDriving systemsDistronic*
When activated, the Distronic adaptive
cruise control system increases driving
convenience afforded by the cruise control
during travel on expressways and other
major roads.

If the Distronic distance sensor detects
a slower moving vehicle directly ahead,
your vehicle speed will be reduced so
that you follow that vehicle at a preset
distance.


If there is no vehicle directly ahead of
you, Distronic will function in the same
way as cruise control (
page 195).
Warning!
G
Distronic adaptive cruise control is no sub-
stitute for active driving involvement. It does
not react to stationary objects, nor recog-
nize or predict the curvature and lane layout
or the movement of vehicles ahead. Distron-
ic can only apply a maximum of 20% of the
vehicle’s braking power.
It is the driver’s responsibility at all times to
be attentive to traffic and road conditions
and to provide the steering, braking and oth-
er driving inputs necessary to retain control
of the vehicle.Warning!
G
Distronic is a convenience system. Its speed
adjustment reduction capability is intended
to make cruise control more effective and
usable when traffic speeds vary. However, it
is not intended to, nor does it, replace the
need for extreme care. The responsibility for
the vehicle speed and the distance to the ve-
hicle ahead, including most importantly
brake operation to assure safe stopping dis-
tance, always rests with the driver.
Distronic cannot take street and traffic con-
ditions into account.
Warning!
G
Distronic requires familiarity with its opera-
tional characteristics. We strongly recom-
mend that you review the following
information carefully before operating the
system.iFor operation in the USA only: This de-
vice complies with Part 15 of the
FCC Rules. Operation is subject to the
following two conditions:

This device may not cause harmful
interference, and


this device must accept any inter-
ference received, including interfer-
ence that may cause undesired
operation.
Any unauthorized modification to this
device could void the user’s authority
to operate the equipment.

208 Controls in detailDriving systems
The most likely cause for a malfunctioning
system is a dirty sensor (located behind
the hood grille), especially at times of snow
and ice or heavy rain. In such a case, Dis-
tronic will switch off, and the message CURRENTLY UNAVAILABLE SEE OPER.
MANUAL
appears in the multifunction dis-
play.
For cleaning and care of the Distronic sen-
sor, see “Cleaning the Distronic* system
sensor cover” (
page 287).Turns and bends
In turns or bends, Distronic may not detect
a moving vehicle in front, or it may detect
one too soon. This may cause your vehicle
to brake late or unexpectedly.
Distronic regulates only the distance be-
tween your vehicle and those directly ahead
of it, but does not register stationary objects
in the road, e.g.:

a stopped vehicle in a traffic jam


a disabled vehicle


an oncoming vehicle
The driver must always be on the alert, ob-
serve all traffic and intercede as required by
steering or braking the vehicle.
Warning!
G
Distronic should not be used in snowy or icy
road conditions.
iIf the message
CURRENTLY UNAVAILABLE
SEE OPER. MANUAL
disappears during
driving and the last speed stored flash-
es for approximately five seconds, the
dirt (e.g. slush) has dissolved; Distronic
is again operational.


214 Controls in detailDriving systemsParktronic system* (Parking assist)
The Parktronic system is an electronic aid
designed to assist the driver during park-
ing maneuvers. It visually and audibly indi-
cates the relative distance between the
vehicle and an obstacle.
The Parktronic system is automatically ac-
tivated when you switch on the ignition
and release the parking brake. The Park-
tronic system deactivates at speeds over
11 mph (18 km/h). At lower speeds the
Parktronic system turns on again.The Parktronic system monitors the sur-
roundings of your vehicle with six sensors
in the front bumper and four sensors in the
rear bumper.
1Sensors in the front bumperWarning!
G
The Parktronic is a supplemental system. It
is not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always rests with the driver.
Special attention must be paid to objects
with smooth surfaces or low silhouettes
(e.g. trailer couplings, painted posts, or road
curbs). Such objects may not be detected by
the system and can damage the vehicle.
The operational function of the Parktronic
system can be affected by dirty sensors, es-
pecially at times of snow and ice, see
“Cleaning the Parktronic system sensors”
(page 287).
Interference caused by other ultrasonic sig-
nals (e.g. working jackhammers or the air
brakes of trucks) can cause the system to
send erratic indications, and should be tak-
en into consideration.
Warning!
G
Make sure that no persons or animals are in
the area in which you are maneuvering. You
could otherwise injure them.

215 Controls in detail
Driving systems
Range of the sensors
To function properly, the sensors must be
free of dirt, ice, snow and slush. Clean the
sensors regularly, being careful not to
scratch or damage the sensors.Front sensors
Rear sensorsMinimum distance
If the system detects an obstacle in this
range, all the warning lamps come on and
you hear a warning signal. If the obstacle is
closer than the minimum distance, the ac-
tual distance might no longer be indicated
by the system.
Center
approx. 40 in (100 cm)
Corners
approx. 24 in (60 cm)
Center
approx. 48 in (120 cm)
Corners
approx. 32 in (80 cm)
!During parking maneuvers, pay special
attention to objects located above or
below the height of the sensors (e.g.
planters or trailer hitches). The Park-
tronic system will not detect such ob-
jects at close range and damage to
your vehicle or the object may result.
Ultrasonic signals from outside sourc-
es (e.g. truck air brakes or jackham-
mers) may impair the operation of the
Parktronic system.
Center
approx. 8 in (20 cm)
Corners
approx. 6 in (15 cm)

273 Operation
Tires and wheels
Checking tire pressure electronically*
(vehicles produced up to approximate-
ly October 2003)
The tire inflation pressure monitor only
functions on wheels that are equipped with
the proper electronic sensors. It monitors
the tire inflation pressure, as selected by
the driver, in all four tires. A warning is is-
sued to alert you to a decrease in pressure
in one or more of the tires.
Tire pressure inquiries are made using the
multifunction display (
page 129). The in-
flation pressures are displayed only after a
few minutes travel time.
You can select the unit of measure used for
the tire inflation pressure by changing the
setting in the control system (
page 129).

Switch on ignition.

Press buttonè orÿ on the mul-
tifunction steering wheel repeatedly
until the standard display menu ap-
pears in the multifunction display
(page 129).

Press button k orj repeatedly
until you see the current inflation pres-
sures for each tire appear in the dis-
play.
iCheck with an authorized
Mercedes-Benz Center to determine
the equipment installed in your vehicle.
iPossible differences between the read-
ings of a tire pressure gauge of an air
hose, e.g. gas station equipment, and
the vehicle’s control system can occur.
The readings issued by the control sys-
tem are more precise.
Warning!
G
The tire inflation pressure monitor does not
indicate a warning for wrongly selected in-
flation pressures. Always adjust tire inflation
pressure according to the label on the fuel
filler flap.
The tire inflation pressure monitor is not
able to issue a warning due to a sudden dra-
matic loss of pressure (e.g. tire blowout
caused by a foreign object). In this case
bring the vehicle to a halt by carefully apply-
ing the brakes and avoiding abrupt steering
maneuvers.iOperating radio transmission equip-
ment (e.g. wireless headsets, two-way
radios) in or near the vehicle could
cause the tire inflation pressure moni-
tor to malfunction.

320 Practical hintsWhat to do if …?Tire pressure monitor messages
(vehicles produced up to approximately
October 2003)Display symbol
Display message
Possible cause
Possible solution
H
TIRE PRES.

DISPLAY AFTER DRIVING
A FEW MINS. REACTIVATE
USING R-BUTTON
The tire pressure is being checked.
TIRE PRES. MONITOR
NOT ACTIVE
The tire inflation pressure monitor* is un-
able to monitor the tire pressure due to

the presence of several wheel sensors
in the vehicle.


excessive wheel sensor tempera-
tures.


a nearby radio interference source.


unrecognized wheel sensors mount-
ed.

Check the tire pressure at the next ser-
vice station.
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.

321 Practical hints
What to do if …?
Display symbol
Display message
Possible cause
Possible solution
H
TIRE PRES. MONITOR
REACTIVATE!
The tire inflation pressure monitor* is de-
activated.

Activate the tire inflation pressure mon-
itor* (
page 274).
TIRE PRES. MONITOR
VISIT WORKSHOP!
The tire inflation pressure monitor* is
malfunctioning.

Have the tire inflation pressure moni-
tor* checked by an authorized
Mercedes-Benz Center.

Change the wheel (
page 343).
A wheel without proper sensor was in-
stalled.

Check and correct tire pressure as re-
quired (
page 271).
TIRE PRES.
CAUTION, TIRE DEFECT!
One or more tires are deflating.

Carefully bring the vehicle to a halt,
avoiding abrubt steering and braking
maneuvers.

Change the wheel (
page 343).
TIRE PRES.
CHECK TIRES!
The tire pressure in one or more tires is
already below the minimum value.
The tire pressure in one or more tires is
low.

Carefully bring the vehicle to a halt,
avoiding abrubt steering and braking
maneuvers.

Change the wheel (
page 343).
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.

328 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
H
TIRE PRES. MONITOR
REACTIVATED
The tire pressure monitor is using the current
pressure values as the basis for monitoring.
TIRE PRES. MONITOR
CURRENTLY
UNAVAILABLE
The tire pressure monitor is temporarily inop-
erative because:

an additional wheel sensor is in the vehi-
cle


the maximum temperature of the wheel
sensor has been exceeded


a radio source is causing interference


unrecognized wheel sensors have been
installed

Remove any additional wheel sensors
from the vehicle
As soon as the causes of the malfunction
have been removed, the tire inflation
pressure monitor automatically becomes
active again.
TIRE PRES. MONITOR
NOT OPERATIONAL
DRIVE TO WORKSHOP
The tire pressure monitor or a wheel sensor
is malfunctioning.

Have the tire inflation pressure moni-
tor checked by an authorized
Mercedes-Benz Center.
A wheel without proper sensor was installed.

Have the wheels checked.
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.