ABS MERCEDES-BENZ ML500 1997 Complete Workshop Manual

77 Safety and Security
Driving and safety systems
Braking
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 pul-
sation.
Continuous, steady brake pedal pressure
yields the advantages provided by the ABS,
namely braking power and the ability to
steer the vehicle.
The pulsating brake pedal can be an indica-
tion of hazardous road conditions and
functions as a reminder to take extra care
while driving.Emergency brake maneuver

Keep continuous full pressure on the
brake pedal.LOW RANGE– ABS
During off-road driving, a special low range
system for the ABS is operational with
transmission in LOW RANGE mode
(
page 125).
When applying the service brakes at
speeds below approximately
18 mph (30 km / h), the front wheels are
locked cyclically to shorten the braking
distance (dig-in effect). This affects steer-
ing the vehicle.
iWith the ABS malfunctioning, the BAS,
the EBP, ESP, and the 4-ETS are also
switched off.
Normal driving and braking functions
are still available.

78 Safety and SecurityDriving and safety systemsFor more information, see “The yellow ABS
warning lamp comes on while driving.”
(page 242).
BAS
The Brake Assist System (BAS) operates in
emergency situations. If you apply the
brakes very quickly, the BAS automatically
provides full brake boost, thereby poten-
tially reducing braking distance. Apply con-
tinuous full braking pressure until the
emergency braking situation is over. The
ABS will prevent the wheels from locking.
When you release the brake pedal, the
brakes function again as normal. The BAS
is then deactivated.
The ¿indicator lamp in the instrument
cluster (
page 25) comes on when you
turn the key to position2. It goes out when
the engine is running.
For more information, see “The yellow
BAS / ESP malfunction indicator lamp
comes on while driving.” (
page 246).
Warning!
G
The ABS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking or steering efficiency be-
yond that afforded by the condition of the
vehicle brakes and tires or the traction af-
forded. The ABS cannot prevent accidents,
including those resulting from excessive
speed in turns, following another vehicle too
closely, or hydroplaning. Only a safe, atten-
tive, and skillful driver can prevent acci-
dents. The capabilities of an ABS equipped
vehicle must never be exploited in a reck-
less or dangerous manner which could jeop-
ardize the user’s safety or the safety of
others.
Warning!
G
The BAS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking efficiency beyond that af-
forded 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, fol-
lowing another vehicle too closely, or hydro-
planing. Only a safe, attentive, and skillful
driver can prevent accidents. The capabili-
ties of a BAS equipped vehicle must never
be exploited in a reckless or dangerous
manner which could jeopardize the user’s
safety or the safety of others.

120 Controls in detailAutomatic transmissionOne-touch gearshifting
Even with an automatic transmission you
can change the gears manually when the
gear selector lever is in positionD.
Downshifting
Briefly press the gear selector lever to
the left in the D–direction.
The transmission will shift from the current
gear to the next lower gear. This action
simultaneously limits the gear range of the
transmission (
page 121).Upshifting

Briefly press the gear selector lever to
the right in the D+direction.
The transmission will shift from the current
gear to the next higher gear as permitted
by the shift program. This action simul-
taneously extends the gear range of the
transmission.Canceling gear range limit

Press and hold the gear selector lever
in the D+direction until D reappears in
the tachometer display.
The transmission will shift from the current
gear range directly to gear rangeD.
Shifting into optimal gear range

Press and hold the gear selector lever
in the D– direction.
The transmission will automatically select
the gear range suited for optimal
acceleration and deceleration. This will
involve shifting down one or more gears.
Warning!
G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced
vehicle control. Your vehicle’s ABS will not
prevent this type of loss of control.
iTo avoid overrevving the engine when
the gear selector lever is moved to
the D– direction, the transmission will
not shift to a lower gear if the engine’s
max. speed would be exceeded.

150 Controls in detailDriving systems
Driving systemsThe driving systems of your vehicle are de-
scribed on the following pages:

Cruise control, with which the vehicle
can maintain a preset speed.


Parktronic*, with which you can assist
your parking maneuvers.
The driving systems BAS, ABS, ESP, EBB
and 4-ETS, are described in the “Safety
and Security” section (
page 76).
Cruise control
Cruise control automatically maintains the
speed you set for your vehicle.
Use of cruise control is recommended for
driving at a constant speed for extended
periods of time. You can set or resume
cruise control at any speed over 20 mph
(30 km / h).
The cruise control function is operated by
means of the cruise control lever.
The cruise control lever is the uppermost
lever found on the left-hand side of the
steering column (
page 23).
Warning!
G
Cruise control is a convenience system de-
signed to assist the driver during vehicle op-
eration. The driver is and must remain
responsible for the vehicle speed and for
safe brake operation.
Only use cruise control if the road, traffic
and weather conditions make it advisable to
travel at a steady speed.

The use of cruise control can be danger-
ous on winding roads or in heavy traffic
because conditions do not allow safe
driving at a steady speed.


The use of cruise control can be danger-
ous on slippery roads. Rapid changes in
tire traction can result in wheel spin and
loss of control.


Deactivate cruise control when driving
in fog.
The “Resume” function should only be oper-
ated if the driver is fully aware of the previ-
ously set speed and wishes to resume this
particular preset speed.

199 Operation
Driving instructions
Road salts and chemicals can adversely af-
fect braking efficiency. Increased pedal
force may become necessary to produce
the normal brake effect.
Depressing the brake pedal periodically
when traveling at length on salt-strewn
roads can bring road-salt-impaired braking
efficiency back to normal.If the vehicle is parked after being driven
on salt-treated roads, the braking efficien-
cy should be tested as soon as possible af-
ter driving is resumed.
For more information, see "Winter driving"
(
page 230).
Warning!
G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced vehi-
cle control. Your vehicle’s ABS will not pre-
vent this type of control loss.
Do not engage the transfer case in position
LOW when driving on ice or packed snow. At
speeds below 18 mph (30 km / h) vehicle
steering is adversely affected by the LOW
RANGE - ABS (
page 77).
Warning!
G
Make sure not to endanger any other road
users when carrying out these braking ma-
neuvers.Warning!
G
If the vehicle becomes stuck in snow, make
sure that snow is kept clear of the exhaust
pipe and from around the vehicle with the
engine running. Otherwise, deadly carbon
monoxide (CO) gases may enter vehicle in-
terior resulting in unconsciousness and
death.
To assure sufficient fresh air ventilation,
open a window slightly on the side of the ve-
hicle not facing the wind.
Warning!
G
The outside temperature indicator is not de-
signed to serve as an ice-warning device and
is therefore unsuitable for that purpose. In-
dicated temperatures just above the freez-
ing point do not guarantee that the road
surface is free of ice.

201 Operation
Driving instructions
Special driving features for off-road
driving
The following driving features are available
for specific kind of operation:

LOW RANGE mode (
page 125)


LOW RANGE – ABS (
page 77)


LOW RANGE – 4-ETS (
page 80)


LOW RANGE – ESP (
page 81)
Off-road driving rules
Engage the LOW RANGE mode before driv-
ing under off-road conditions
(
page 125).
Fasten items being carried as securely as
possible (
page 157).Checklist before off-road driving
Tires


Check the tread depth and maintain
specified tire pressure (see tire pres-
sure label inside the fuel filler flap).


Check tires for possible damage and
remove foreign objects.


Replace missing valve caps.
iWe recommend keeping doors, liftgate,
windows, and sliding / pop-up roof*
closed whenever driving in off-road
mode.
!Observe the following during off-road
driving:

Adjust vehicle speed to condition of
terrain. The more uneven, rutty and
steeper the terrain, the lower the
speed should be


Watch out for obstacles, such as
rocks, holes, tree stumps and ruts.


Be especially careful when driving
in unknown territory. It may be nec-
essary to get out of the vehicle and
scout the path you intend to take.


Before driving through water, deter-
mine is depth.


Do not stop vehicle while immersed
in water, and do not shut off the
engine.


In sandy soil, please drive at a
steady speed as allowed by condi-
tions. This helps overcome the vehi-
cle rolling resistance and reduces
the likelihood of the vehicle sinking
into the ground.


Do not initiate jumps with the vehi-
cle. It interrupts the forward mo-
mentum of the vehicle.


Always drive onto slopes with the
the engine running and the vehicle
in gear.

203 Operation
Driving instructions
The 4-ETS recognizes the situation and
limits the torque for the front wheels by
braking them. Simultaneously the
torque for the rear wheels is increased.
Driving across a hilltop


Decelerate just ahead of a hilltop (do
not select gear rangeN), to prevent the
vehicle from speeding up too much af-
ter climbing a hill.
Use the momentum of the vehicle to
drive across the hilltop.
Driving in this manner prevents the ve-
hicle from jumping across the hilltop
and thus loosing its forward momen-
tum.Driving downhill


Select gear range1 on the automatic
transmission (
page 121).


Drive downhill observing the same
rules as driving uphill (
page 202).


The special LOW RANGE – ABS setting
allows for precise and brief (cyclical)
blocking of the front wheels, permitting
them to dig into loose ground.
Remember that the front wheels when
stopped, slide across a surface, thus
loose their ability to steer the vehicle.Driving through water
120 in (50 cm)


Before driving through water, deter-
mine its depth.
It should not be deeper than approxi-
mately 20 inches (50 cm).
Make sure you check the water bed.
The ground surface may not be firm
which may result in deeper waters than
expected when driving the vehicle
through it.


Switch to LOW RANGE mode before
driving through water (
page 125).

230 OperationWinter driving
Winter drivingBefore the onset of winter, have your vehi-
cle winterized at an authorized
Mercedes-Benz Light Truck Center. This
service includes:

Check of anticorrosion and antifreeze
concentration.


Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“S” to a premixed windshield washer
solvent / antifreeze which is formulated
for temperatures below freezing point
(page 307).


Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to ensure
that the engine can be started even at
low ambient temperatures.


Tire change. Mercedes-Benz recom-
mends M+S rated radial-ply tires with a
minimum tread depth of approximately 1/6in (4 mm) on all four wheels for the
winter season.
Winter tires
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. Use of winter tires
is the only way to achieve the maximum ef-
fectiveness of the ABS, ESP, 4-ETS, and
EBP in winter operation.
For safe handling, ensure that all winter
tires mounted are of the same make and
have the same tread design.Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your ve-
hicle, you must place a notice to this effect
where it will be seen by the driver. Such no-
tices are available at your tire dealer or any
authorized Mercedes-Benz Light Truck
Center.Warning!
G
Winter tires with a tread depth under
1/6in
(4 mm) must be replaced. They are no long-
er suitable for winter operation.
Warning!
G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Light Truck Center.

242 Practical hintsWhat to do if …
What to do if …Lamps in instrument clusterGeneral information:
If a bulb in the instrument cluster fails to
light up during the bulb self-check when turning the key in steering lock to
position2, have it checked and replaced if
necessary.Problem
Possible cause
Suggested solution
-
The yellow ABS warning lamp
comes on while driving.
ABS has detected a malfunction and has
switched off. The BAS, ESP, 4-ETS and EBP
are also switched off.
The brake system is still functioning normally
but without ABS available.

Continue driving with added caution.
Wheels may lock during hard braking
reducing steering capability.

Have the system checked at an autho-
rized Mercedes-Benz Light Truck Cen-
ter as soon as possible.
Failure to follow these instructions in-
creases the risk of an accident.
The charging voltage has fallen below
10 volts. The ABS has switched off.
When the voltage is above this value
again, the ABS is operational again.
If necessary, have the generator
(alternator) and the battery checked.

245 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
É
-
The red brake warning lamp
comes on in addition to the yel-
low ABS malfunction lamp and
you hear a warning sound.
There is a malfunction in the Electronic Brake
Proportioning (EBP) system.
The enhanced braking effect is not available.

Have the system checked immediate-
ly at an authorized Mercedes-Benz
Light Truck Center.
Failure to follow these instructions in-
creases the risk of accidents.
¿
The yellow BAS / ESP malfunc-
tion indicator lamp comes on
while driving.
The self-diagnosis has not been completed.
The BAS / ESP malfunction indicator lamp
will go out after driving a short distance at
more than approx.12 mph (20 km / h).