2005 MERCEDES-BENZ E320CDI brake sensor

235 Controls in detail
Driving systems
Distronic*
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 239).
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.
Distronic 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.iUSA only:
This device complies with Part 15 of
the FCC Rules. Operation is subject to
the following two conditions:
(1) This device may not cause harmful
interference, and
(2) 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.

245 Controls in detail
Driving 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,
Distronic will switch off, and the message Currently unavailable See Operator’s
Manual
appears in the multifunction dis-
play.
For cleaning and care of the Distronic sen-
sor, see “Cleaning the Distronic system
sensor” (page 351).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.
iIf the message
Currently unavailable
See Operator’s Manual
disappears
during driving and the last speed stored
flashes for approximately five seconds,
the dirt (e.g. slush) has dissolved;
Distronic works again.

250 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, re-
lease the parking brake, and placed the
gear selector lever in positionD,R,orN.
The Parktronic system deactivates at
speeds over approximately 11 mph
(18 km/h). At lower speeds the Parktronic
system turns on again.
The Parktronic system also deactivates
when you place the gear selector lever in
positionP or depress the parking brake
pedal.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 bumper
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, see
“Cleaning the Parktronic system* sensors”
(
page 351).
Warning!
G
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 351).
Interference caused by other ultrasonic sig-
nals (e.g. working jackhammers, car wash or
the air brakes of trucks) can cause the sys-
tem to send erratic indications, and should
be taken into consideration.
Warning!
G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.

251 Controls in detail
Driving systems
Front sensors
Rear sensorsMinimum distance
If the system detects an obstacle in this
range, all the distance warning segments
illuminate and you hear a warning signal. If
the obstacle is closer than the minimum
distance, the actual 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
Parktronic system will not detect such
objects at close range and damage to
your vehicle or the object may result.
Ultrasonic signals from outside sourc-
es (e.g. truck air brakes, car wash or
jackhammers) may impair the opera-
tion of the Parktronic system.
Center
approx. 8 in (20 cm)
Corners
approx. 6 in (15 cm)

252 Controls in detailDriving systemsWarning indicators
Visual signals indicate to the driver the rel-
ative distance between the sensors and an
obstacle. The warning indicator for the
front area is located above the center air
vents in the dashboard. The warning indi-
cator for the rear area is integrated in the
rear trim.Front area warning indicator1Left side of the vehicle
2Right side of the vehicle
3Readiness indicatorsEach warning indicator is divided into five
yellow and two red segments for either
side of the vehicle. The Parktonic system is
operational when the yellow readiness
indicators3 are illuminated.
The position of the gear selector lever de-
termines which warning indicators will be
activated.
As your vehicle approaches an object, one
or more segments will come on, depending
on the distance. When the seventh seg-
ment illuminates, you have reached the
minimum distance.


Front area: An intermittent acoustic
warning will sound as the first red dis-
tance segment illuminates and a con-
stant acoustic warning lasting a
maximum of two seconds will sound for
the second red distance segment. The
signal is canceled when the gear selec-
tor lever is placed in positionP or the
parking brake is activated.


Rear area: An intermittent acoustic
warning will sound as the first red dis-
tance segment illuminates and a con-
stant acoustic warning lasting a
maximum of two seconds will sound for
the second red distance segment. The
signal is canceled when the gear selec-
tor lever is placed in position D,P or
the parking brake is activated.
Gear selector le-
ver position
Warning indicator
D
Front area activated
R or N
Front and rear area
activated
P
Neither activated

396 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
H
Tire pres. monitor
reactivated
The tire pressure monitoring system is
using the current pressure values as the
basis for monitoring.
Tire pressure

displayed only
after driving
a few mins.
The tire inflation pressure is being
checked.
Tire pres. monitor
temporarily
unavailable
The tire pressure monitoring system* is
unable to monitor the tire inflation pres-
sure 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.

Remove any extra wheel sensors from
the vehicle.
As soon as the causes of the malfunction
have been removed, the tire pressure
monitoring system automatically be-
comes active again.
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
excessive heat build-up and possibly a fire.

397 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
H
Tire pres. monitor
reactivated
The tire pressure monitoring system is
using the current pressure values as the
basis for monitoring.
Tire pressure

displayed only
after driving
a few mins.
The tire inflation pressure is being
checked.
Tire pres. monitor
temporarily
unavailable
The tire pressure monitoring system* is
unable to monitor the tire inflation pres-
sure 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.

Remove any extra wheel sensors from
the vehicle.
As soon as the causes of the malfunction
have been removed, the tire pressure
monitoring system automatically be-
comes active again.
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
excessive heat build-up and possibly a fire.

398 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
H
Reactivate
tire pres. monitor
after corr. pres.
There was a tire pressure warning mes-
sage.
The yellow warning lamp for the tire pres-
sure monitoring system comes on and
you have not reactivated the system
since the last tire pressure warning mes-
sage.

Reactivate the tire pressure monitor-
ing system after correcting the tire
pressure values (
page 324).
Tire pres. monitor
deactivated
Drive to workshop
The tire pressure monitoring system is
malfunctioning.
A wheel without proper sensor was in-
stalled.

Have the tire pressure monitoring sys-
tem checked by an authorized
Mercedes-Benz Center.

Change the wheel (
page 425).
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.