check engine light MERCEDES-BENZ ML320 1997 Complete User Guide

197 Driving systems
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index 3Canceling
To cancel the cruise control, briefly push lever to
position 3.
When you step on the brake pedal or the vehicle
speed drops below approximately 25 mph
(40 km / h), for example when driving upgrade, the
cruise control will be canceled.
If the cruise control cancels by itself and remains
inoperative until the engine is restarted, have the
system checked at your authorized Mercedes-Benz
Light Truck Center as soon as possible.
4Resume
If the lever is briefly pushed to position 4 when
driving at a speed exceeding approximately 25 mph
(40 km / h), the vehicle resumes the speed which
was set prior to the cancellation of the cruise
control. The last memorized speed is canceled when
the key in the steering lock is turned to position 1
or 0.Important!
Moving gear selector lever to position “N” switches the
cruise control off.
Wa r n i n g !
Only use the cruise control if the traffic and
weather conditions make it advisable to travel at a
steady speed.• The use of cruise control can be dangerous 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 dangerous on
slippery roads. Rapid changes in tire adhesion
can result in wheel spin and loss of control.The “Resume” function should only be operated if
the driver is fully aware of the previously set speed
and wishes to resume this particular preset speed.

200 Driving systems
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
The BAS / ESP 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.
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. 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 and
the ESP are switched off. When the voltage is above this
value again, the malfunction indicator lamp should go
out and the BAS is operational.
With the ABS malfunctioning, the BAS is also switched
off. Both malfunction indicator lamps come on with the
engine running.
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.

202 Driving systems
Te ch n ica 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 211.
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.

203 Driving systems
Te ch n ica 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 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 255), 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.

204 Driving systems
Te ch n ica 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 211.
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 f lash.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.

206 Driving systems
Te ch n ica 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.
After driving off the BAS / ESP malfunction indicator
lamp should go out after approximately 110 - 220 yd
(100 - 200 m).

215 Check regulary and before a long trip
Te ch n ica 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 233 and
“Engine oil level indicator” on page 89.
2Coolant level
See “Coolant level” on page 234.
3Brake fluid
See “Brake fluid” on page 294.
4Windshield washer system/
Headlamp cleaning system/
Rear window washer system
For refilling reservoir see page 236.
Opening hood, see page 231.
Ve h i c l e l i g h t i n g : Check function and cleanliness. For
replacement of light bulbs, see “Exterior lamps” on
page 260.
Exterior lamp switch, see page 90.

218 Malfunction and indicator lamps
Te ch n ica 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 220 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

219 Malfunction and indicator lamps
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index Brake warning lamp
When the brake warning lamp appears
while the engine is running, this means:
•there is insufficient brake fluid in the reservoir
(engine running and parking brake released), or
•the parking brake is set (engine running)
•the electronic brake proportioning (EBP) system is
malfunctioning.
Note:
If you find that the minimum mark on the brake fluid
reservoir is reached, have the brake system checked for
brake pad thickness and leaks.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 56 for notes on airbags, page 55 for belt
tensioners, and page 65 for infant and child seat
restraints.
Wa r n i n g !
Driving with the brake warning lamp illuminated
can result in an accident. Have your brake system
checked immediately if the brake warning lamp
stays on. Don’t add brake fluid before checking the
brake system. Overfilling the brake fluid reservoir
can result in spilling brake fluid on hot engine
parts and the brake fluid catching fire. You can be
seriously burned.BRAKE
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

222 Malfunction and indicator lamps
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
ABS malfunction indicator lamp
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, ESP and 4-ETS+
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
switched off. When the voltage is above this value again,
the malfunction indicator lamp should go out and the
ABS is operational.
Have the system checked at your authorized
Mercedes-Benz Light Truck Center as soon as possible.
See page 201 for notes on antilock brake system (ABS).Adjustable steering wheel – indicator lamp
The indicator lamp in the instrument cluster
comes on with the key in steering lock
position 2 and should go out with the engine
running.
If the indicator lamp does not go out after starting the
engine, the adjustable steering column is not properly
locked.
For locking the adjustable telescoping steering column,
see page 70.
AIRBAG OFF indicator lamp
The indicator lamp will light up for
approximately 6 seconds, extinguish, then
blink once, when you turn the key in
steering lock to position 1 or 2.
The 7 indicator lamp stays lit as long as a
BabySmart
TM compatible child seat is properly installed
on the front passenger seat. It indicates that the front
passenger airbag is switched off.
See page 53 for BabySmart
TM airbag and its deactivation
system.
BabySmart
TM is a trademark of Siemens Automotive Corp.
ABS