2002 MERCEDES-BENZ ML320 Engine light

219 Driving systems
Te ch n i c a l
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.
ABS control
The ABS malfunction indicator lamp- in the
instrument cluster comes on with the 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.
With the ABS malfunctioning, the BAS, EBP, ESP and
4-ETS+ are also switched off. The malfunction indicator
lamps come on with the engine running.
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.

220 Driving systems
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
If the charging voltage falls below 10 volts, the
malfunction indicator lamp comes on and the ABS is
switched off. When the voltage is above this value again,
the malfunction indicator lamp should go out and the
ABS is operational.
If the ABS malfunction indicator lamp stays illuminated,
have the system checked at your authorized
Mercedes-Benz Light Truck Center as soon as possible.Notes:
To alert following vehicles to slippery road conditions
you discover, operate your hazard warning flashers as
appropriate.
Operating the vehicle on a single axle dynamometer
should only be done for briefly testing the brakes. To do
so, move selector lever to position “N”. The engine must
be shut off (key in steering lock position 0 or 1).
LOW RANGE – ABS
During off-road driving a special low range system for
the antilock brake system (ABS) is operational with
transmission in LOW RANGE mode, see page 229.
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 steering the vehicle.
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
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Four-wheel electronic traction system (4-ETS+)
With the key in steering lock position 2, the yellow
4-ETS+ malfunction indicator lamp{ and the 4-ETS+
warning lampv come on and should go out when
the engine is running.
The 4-ETS+ improves vehicle’s ability to utilize available
traction, especially under slippery road conditions. The
brakes are applied to the spinning wheel and power is
transferred to the wheel(s) with traction.
The traction control engages at vehicle speeds up to
approx. 24 mph (40 km / h), and switches off at
50 mph (80 km / h).
The 4-ETS+ warning lampv, located in the
speedometer dial, starts to flash at any vehicle speed, as
soon as the tires lose traction and the wheels begin to
spin.
Important!
If the 4-ETS+ warning lampv flashes:
•During take-off, apply as little throttle as possible.
•While driving, ease up on the accelerator.
•Adapt your speed and driving to the prevailing road
conditions.4-ETS+ Control
If the yellow 4-ETS+ malfunction indicator lamp{
comes on while the 4-ETS+ warning lampv flashes,
the electronic traction system is being switched off
temporarily to prevent overheating of the drive wheel
brakes.
If the 4-ETS+ malfunction indicator lamp{ comes on
with the engine running, a malfunction has been
detected.
Have the 4-ETS+ checked at your authorized
Mercedes-Benz Light Truck Center as soon as possible.
With the ABS malfunctioning, the 4-ETS+ is also
switched off.
Caution!
If the vehicle is towed with the front axle raised (see
towing the vehicle on page 277), or when testing the
parking brake on a brake test dynamometer, the engine
must be shut off (key in steering lock position 0 or 1).
Otherwise, the electronic traction system will
immediately be engaged and will apply the rear wheel
brakes.

222 Driving systems
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Note:
In winter operation, the maximum effectiveness of the
electronic traction system is only achieved with
Mercedes-Benz recommended M+S rated radial-ply tires
and / or snow chains.
LOW RANGE – 4-ETS+
During off-road driving a special low range system for
the four wheel electronic traction system (4-ETS+) is
operational with transmission in LOW RANGE mode,
see page 229.
If one or more tires lose traction while driving downhill
(accelerator released), the 4-ETS+ engages and the
warning lampv, located in the speedometer dial,
starts to flash.Electronic brake proportioning (EBP)
The EBP enhances braking effectiveness by allowing the
rear brakes to supply a greater proportion of the braking
effort without a loss of vehicle stability.
If a warning tone sounds for five seconds and the
symbols É and - are displayed in the instrument
cluster, the system has detected a malfunction and is
switched off. Have the system checked immediately at
an authorized Mercedes-Benz Light Truck Center.
Failure to do so could result in an accident, since the
enhanced braking effect is not available when the
system is switched off.
Note:
When the EBP is switched off, every time the engine is
started, a warning tone will sound for five seconds and
the symbols É and - will light up. In addition,
whenever the brakes are applied at speeds exceeding
25 mph (40 km / h), the warning tone sounds for five
seconds.

224 Driving systems
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
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 BAS / ESP malfunction indicator lamp stays
illuminated, have the BAS or ESP checked at your
authorized Mercedes-Benz Light Truck 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 lampv 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.
If battery voltage drops below 10 volts, the indicator
lamp comes on and the brake assist system (BAS) is
deactivated. If the battery voltage rises and exceeds
10 volts, the BAS / ESP malfunction indicator lamp goes
out, and brake assist system (BAS) is functional again.
After driving off the BAS / ESP malfunction indicator
lamp should go out after approximately 110 - 220 yd
(100 - 200 m).

238 Check regulary and before a long trip
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Check regularly and before a long trip 1Engine oil level
See “Checking engine oil level” on page 255 and
“Engine oil level indicator” on page 96.
2Coolant level
See “Coolant level” on page 256.
3Brake fluid
See “Brake fluid” on page 316.
4Windshield washer system/
Headlamp cleaning system/
Rear window washer system
For refilling reservoir see page 258.
Opening hood, see page 253.
Vehicle lighting: Check function and cleanliness. For
replacement of light bulbs, see “Exterior lamps” on
page 282.
Exterior lamp switch, see page 97.

240 Malfunction and indicator lamps
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
Malfunction and indicator lamps
in the instrument cluster
General 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 position 2, have it checked and replaced
if necessary.
On-board diagnostic system
Check engine malfunction indicator lamp
Engine malfunction indicator lamp. If the
“CHECK ENGINE” malfunction indicator
lamp comes on when the engine is running,
it indicates a malfunction of the fuel management
system, emission control system, systems which impact
emissions, or the fuel cap is not closed tight (check the
fuel cap). If the “CHECK ENGINE” lamp is illuminated
continuously and the vehicle is driving normally, you
may still drive the vehicle, however, in all cases, we
recommend that you have the system checked at your
authorized Mercedes-Benz Light Truck Center as soon
as possible.
If the “CHECK ENGINE” lamp comes on continuously
and / or the vehicle is not driving normally (e.g.
malfunction of the fuel management system or running out of fuel), serious damage can occur to the emission
system. Please contact your authorized Mercedes-Benz
Light Truck Center immediately.
The Sequential Multiport Fuel Injection (SFI) control
module monitors emission control components that
either provide input signals to or receive output signals
from the control module. Malfunctions resulting from
interruptions or failure of any of these components are
indicated by the “CHECK ENGINE” malfunction
indicator lamp in the instrument cluster and are
simultaneously stored in the SFI control module.
If the “CHECK ENGINE” malfunction indicator lamp
comes on, have the system checked at your authorized
Mercedes-Benz Light Truck Center as soon as possible.
With some exceptions, the control module switches off
the “CHECK ENGINE” malfunction indicator lamp if the
condition, causing the lamp to come on, no longer exists
during three consecutive cycles. See also page 242 for
fuel cap placement warning.
An on-board diagnostic connector is located in the
passenger compartment near to the parking brake
pedal, allowing the accurate identification of system
malfunctions through the readout of diagnostic trouble
codes.
CHECK
ENGINE

242 Malfunction and indicator lamps
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
Supplemental restraint system (SRS) indicator lamp
The operational readiness of the airbag
system is verified by the indicator lamp
“SRS” in the instrument cluster when
turning the key in steering lock to position 1 or 2. If no
fault is detected, the lamp will go out after
approximately 5 seconds; after the lamp goes out, the
system continues to monitor the components and
circuitry of the airbag system and will indicate a
malfunction by coming on again.
See page 58 for notes on airbags, page 57 for belt
tensioners, and page 68 for infant and child seat
restraints.Fuel reserve warning
When the warning lamp (1) comes on after starting the
engine, or if it comes on while driving, it indicates that
the fuel level is down to the reserve quantity of
approximately 3.2 gal (12 liters).
See page 235 for notes on refueling the vehicle.
Wa r n i n g !
In the event a malfunction of the “SRS” is indicated
as outlined above, the “SRS” may not be
operational. For your safety, we strongly
recommend that you visit an authorized
Mercedes-Benz Light Truck Center immediately to
have the system checked; otherwise the “SRS” may
not be activated when needed in an accident, which
could result in serious or fatal injury, or it might
deploy unexpectedly and unnecessarily which
could also result in injury.SRS