2001 MERCEDES-BENZ E320 ABS

215 Driving systems
Technical
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Brake assist system (BAS)The BAS is designed to maximize the vehicle’s braking
capability during emergency braking maneuvers by
having maximum power boost applied to the brakes
more quickly in emergency braking conditions than
might otherwise be afforded solely by the driver’s
braking style. This can help reduce braking distances
over what ordinary driving and braking style might do.
The BAS complements the antilock brake system (ABS).
Applying the brakes very quickly results in maximum
BAS assistance.
To receive the benefit of the system you must apply
continuous full braking power during the stopping
sequence. Do not reduce brake pedal pressure.
Once the brake pedal is released, the BAS is deactivated.
Wa r n i n g !
BAS cannot prevent the natural laws of physics
from acting on the vehicle, nor can it increase
braking efficiency beyond that afforded by the
condition of the vehicle brakes and tires or the
traction afforded. The BAS cannot prevent
accidents, including those resulting from excessive
speed in turns, following another vehicle too
closely, or aquaplaning. Only a safe, attentive, and
skillful driver can prevent accidents. The
capabilities of a BAS equipped car must never be
exploited in a reckless or dangerous manner which
could jeopardize the user’s safety or the safety of
others.

216 Driving systems
Technical
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
The malfunction indicator lamps for the ESP are
combined with the BAS malfunction indicator lamp.
The BAS / ESP malfunction indicator lamp in the
instrument cluster comes on with the electronic key in
steering lock position 2 and should go out with the
engine running.
If the BAS / ESP malfunction indicator lamp comes on
permanently while the engine is running, a malfunction
has been detected in either system. As a result, it is
possible that now only partial engine output will be
available, and pressing the accelerator pedal will
require more effort. If the BAS malfunctions, the brake
system functions in the usual manner, but without BAS.If the charging voltage falls below 10 volts, the
malfunction indicator lamp comes on and the BAS is
sw itched of f. Wh en t he voltage is a bove th is value a gain,
the malfunction indicator lamp should go out and the
BAS is operational.
With the ABS malfunctioning, the BAS and ESP is also
switched off. Both malfunction indicator lamps come on
with the engine running.
If a BAS warning message is displayed, have the BAS
and ESP checked at your authorized Mercedes-Benz
Center as soon as possible.

217 Driving systems
Technical
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Antilock brake system (ABS)
Important!
The ABS improves steering control of the vehicle during
hard braking maneuvers.
The ABS prevents the wheels from locking up above a
vehicle speed of approximately 5 mph (8 km / h)
independent of road surface conditions.At the instant one of the wheels is about to lock up, a
slight pulsation can be felt in the brake pedal,
indicating that the ABS is in the regulating mode. Keep
firm and steady pressure on the brake pedal while
experiencing the pulsation.
Continuous steady brake pedal pressure results in
applying the advantages of the ABS, namely braking
power and ability to steer the vehicle.
In the case of an emergency brake maneuver keep
continuous full pressure on the brake pedal. In this
manner only can the ABS be most effective.
On slippery road surfaces, the ABS will respond even
with light brake pedal pressure because of the
increased likelihood of locking wheels. The pulsating
brake pedal can be an indication of hazardous road
conditions and functions as a reminder to take extra
care while driving.
Wa r n i n g !
Do not pump the brake pedal, rather use firm,
steady brake pedal pressure. Pumping the brake
pedal defeats the purpose for ABS and significantly
reduces braking effectiveness.

218 Driving systems
Technical
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
ABS control
The ABS malfunction indicator lamp- in the
instrument cluster comes on with the electronic key in
steering lock position 2 and should go out with the
engine running.
When the ABS malfunction indicator lamp in the
instrument cluster comes on while the engine is
running, it indicates that the ABS has detected a
malfunction and has switched off. In this case, the brake
system functions in the usual manner, but without
antilock assistance.
For ABS malfunction indicator lamp, see page 237.
With the ABS malfunctioning, the BAS and ESP are also
switched off. Both malfunction indicator lamps come on
with the engine running.
If the charging voltage falls below 10 volts, the
malfunction indicator lamp comes on and the ABS is
sw itched of f. W he n t he voltage is a bove this val ue again,
the malfunction indicator lamp should go out and the
ABS is operational.If th e ABS ma lfu nction indicator la mp stays ill uminated ,
have the system checked at your authorized
Mercedes-Benz Center as soon as possible.
Note:
To alert following vehicles to slippery road conditions
you discover, operate your hazard warning flashers as
appropriate.
Wa r n i n g !
ABS cannot prevent the natural laws of physics
from acting on the vehicle, nor can it increase
braking or steering efficiency beyond that afforded
by the condition of the vehicle brakes and tires or
the traction afforded. The ABS cannot prevent
accidents, including those resulting from excessive
speed in turns, following another vehicle too
closely, or aquaplaning. Only a safe, attentive, and
skillful driver can prevent accidents. The
capabilities of an ABS equipped vehicle must never
be exploited in a reckless or dangerous manner
which could jeopardize the user’s safety or the
safety of others.

221 Driving systems
Technical
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Notes:
The malfunction indicator lamp for the ESP is combined
with that of the BAS.
The yellow BAS / ESP malfunction indicator lamp in the
instrument cluster and the yellow ESP warning
lampv in the speedometer dial come on with the
electronic key in steering lock position 2. They should
go out with the engine running.
If the BAS / ESP malfunction indicator lamp comes on
continuously with the engine running, a malfunction
has been detected in either system. Only partial engine
output will be available.
If the BAS malfunctions, the brake system functions in
the usual manner, but without BAS.
If the ESP warning message is displayed, have the BAS
or ESP checked at your authorized Mercedes-Benz
Center as soon as possible.
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
dial comes on). For this reason, all wheels, including the
spare wheel, must have the same tire outside diameter.
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 BAS / ESP malfunction
indicator lamp may be illuminated with the engine
running.
Turn steering wheel completely to the left and then to
the right. The BAS / ESP malfunction indicator lamp
should go out.

233 Contents - Instrument cluster display
Technical
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
Instrument cluster displayMalfunction and
indicator lamps in the
instrument cluster ....................234
On-board diagnostic system .....234
Check engine malfunction
indicator lamp .............................234
Brake warning lamp ..................235
Supplemental restraint
system (SRS)
indicator lamp .............................236
Fuel reserve and fuel cap
placement warning ....................236
Electronic stability program
(ESP) — warning lamp ...............237BAS / ESP malfunction
indicator lamp ............................ 237
ABS malfunction
indicator lamp ............................ 237
Seat belt warning lamp ............. 238
Malfunction and indicator lamp
in the center console ............... 238
AIRBAG OFF
indicator lamp ............................ 238
Malfunction and warning
messages in the
multifunction display .............. 239
DISPLAY DEFECTIVE ................ 240
BATTERY / ALTERNATOR ........ 241
ABS-SYSTEM .............................. 242
BRAKE ASSIST ........................... 242BRAKE LINING WEAR ..............243
BRAKE FLUID .............................243
PARKING BRAKE .......................244
ENGINE FAN ...............................244
COOLANT (coolant level) ..........245
COOLANT TEMP. ........................246
LIGHTING SYSTEM ....................247
LIGHT SENSOR ...........................248
REMOVE KEY .............................248
TELE AID .....................................249
STEERING GEAR OIL .................249
ENGINE OIL LEVEL ...................250
WASHER FLUID ......................... 251
ELEC. STABIL. PROG.
(Electronic stability program) ..252

237 Malfunction and indicator lamps
Technical
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index Electronic stability program (ESP) — warning lamp
The yellow ESP warning lamp in the
speedometer dial comes on with the
electronic key in steering lock position 2.
It should go out with engine running.
See page 219 and 220 if the warning lamp lights up or
flashes when the vehicle is moving.
BAS / ESP malfunction indicator lamp
The malfunction indicator lamp for the ESP
is combined with that of the BAS.
The yellow BAS / ESP malfunction indicator
lamp in the instrument cluster comes on with the
electronic key in steering lock position 2. It should go
out with the engine running.
If the BAS / ESP malfunction indicator lamp remains
illuminated with the engine running, see page 215 for
notes on brake assist system (BAS) and page 220 for
notes on electronic stability program (ESP).ABS malfunction indicator lamp
The ABS malfunction indicator lamp in the
instrument cluster comes on with the
electronic key in steering lock position 2 and
should go out with the engine running.
When the ABS malfunction indicator lamp symbol and
warning in the instrument cluster remains illuminated
while the engine is running, it indicates that the ABS
has detected a malfunction and has switched off. In this
case, the brake system functions in the usual manner,
but without antilock assistance.
With the ABS malfunctioning, the BAS and ESP are also
switched off. Both malfunction indicator lamps come on
with the engine running.
If the charging voltage falls below 10 volts, the
malfunction indicator lamp comes on and the ABS is
sw itched of f. Wh en t he voltage is a bove th is value a gain,
the malfunction indicator lamp should go out and the
ABS is operational.
Have the system checked at your authorized
Mercedes-Benz Center as soon as possible.
See page 217 for notes on antilock brake system (ABS).
ABS

242 Malfunction and warning messages
Technical
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
ABS-SYSTEM
A malfunction has been detected in the system. The
brake system functions in the usual manner, but
without antilock assistance.
With the ABS malfunctioning, the BAS and ESP are also
switched off.
Have the system checked at your authorized
Mercedes-Benz Center as soon as possible.BRAKE ASSIST
A malfunction has been detected in the system. The
brake system functions in the usual manner, but
without BAS.
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ABS-SYSTEM VISIT WORKSHOP!
P54.30-2938-21
Line 1 Line 2
BRAKE ASSIST VISIT WORKSHOP!