MERCEDES-BENZ ML320 1997 Complete Repair Manual

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Driving systems
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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 lamp v, 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.

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Electronic stability program (ESP)
The ESP enhances directional control and reduces
driving wheel spin of the vehicle under various driving
conditions.
Over-/understeering of the vehicle is counteracted by
applying brakes to the appropriate wheel to create a
countervailing vehicle movement. Engine torque is also
limited. The ESP warning lamp, located in the
speedometer dial, starts to flash when ESP is in
operation. Important!
If the ESP warning lamp v 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.
• Do not switch off the ESP.
Caution!
If the vehicle is towed with the front axle raised (see
towing the vehicle on page 255), the engine must be
shut off (key in steering lock position 0 or 1). Otherwise,
the ESP will immediately be engaged and will apply the
rear wheel brakes.
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
lamp v in the speedometer dial come on with the
key in steering lock position 2. They should go out with
the engine running.
Wa r n i n g !
ESP cannot prevent the natural laws of physics
from acting on the vehicle, nor can it increase the
traction afforded. The ESP cannot prevent
accidents, including those resulting from excessive
speed in turns, or aquaplaning. Only a safe,
attentive, and skillful driver can prevent accidents.
The capabilities of an ESP equipped vehicle must
never be exploited in a reckless or dangerous
manner which could jeopardize the user’s safety or
the safety of others.

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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 lamp v 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).

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ESP control switch
ESP control switch located in center console.
To switch ESP off, press upper half of switch.
ESP warning lamp v, located in speedometer dial,
comes on.
To switch ESP on again, press lower half of switch.
ESP warning lamp v, located in speedometer dial,
goes out. To improve the vehicle’s traction when driving with
snow chains, or starting off in deep snow, sand or gravel,
or off-road driving, switch off ESP by pressing the upper
half of the ESP switch. The ESP warning lamp v,
located in the speedometer dial, is continuously
illuminated.
With the ESP system switched off, the engine torque
reduction feature is cancelled. Therefore, the enhanced
vehicle stability offered by ESP is unavailable.
Adapt your speed and driving to the prevailing road
conditions.
A portion of the ESP system remains active, even with
the switch in the OFF position.
P54.25-2037-26
Wa r n i n g !
ESP should not be switched off during normal
driving other than in circumstances described
above. Disabling of the system will reduce vehicle
stability in standard driving maneuvers.
When the ESP warning lamp is illuminated
continuously, the ESP is switched off.
Adapt your speed and driving to the prevailing road
conditions.

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Instruments
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If one drive wheel loses traction and begins to spin, the
brake is applied until the wheel regains sufficient
traction.
Note:
Avoid spinning of one drive wheel. This may cause
serious damage to the drive train which is not covered
by the Mercedes-Benz Limited Warranty.
The ESP warning lamp, located in the speedometer dial,
starts to f lash at any vehicle speed as soon as the tires
lose traction and the wheels begin to spin.
To return to the enhanced vehicle stability offered by
ESP: press lower half of the switch (the ESP warning
lamp in the speedometer dial goes out).
Important!
If the ESP warning lamp f lashes: • during take-off, apply as little throttle as possible,
• while driving, ease up on the accelerator. LOW RANGE – ESP
During off-road driving a special low range system for
the electronic stability program (ESP) is operational
with transmission in LOW RANGE mode, see page 211.
In the LOW RANGE mode the electronic stability
program (ESP) operates in a traction improving fashion
specifically adapted for off-road driving. At speeds
below 27 mph (45 km / h) the ESP assists in over-/
understeering, thus improving vehicle tracking.

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Transmission control – LOW RANGE mode
The switch is located in the instrument panel.
Important!
When switching to or from the LOW RANGE mode,
observe the following:
• The vehicle must be at a complete standstill.
• The engine speed must not exceed 1500 rpm. Failure to do so may result in transmission / engine
damage not covered by the Mercedes-Benz Limited
Warranty
The LOW RANGE mode should be switched on:
• during off-road driving,
• when crossing waters.
For additional practical hints refer to off-road driving
on page 183.
Switching on: 1. Sto p t h e v e h i c l e .
2. Move transmission selector lever to position “N”.
3. Push top end of switch. The LOW RANGE indicator lamp in the instrument cluster blinks slowly during
the changeover.
Once the changeover is complete, the indicator lamp in
the instrument cluster lights up continuously.
Note:
If the indicator lamp blinks fast, one or more switching
conditions were not observed, or the LOW RANGE mode
is defective.

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Switching off: 1. Stop the vehicle.
2. Move transmission selector lever to position “N”.
3. Push top end of switch. The LOW RANGE indicator lamp in the instrument cluster blinks slowly during
the changeover.
Once the changeover is complete, the indicator lamp in
the instrument cluster goes out. Use the gear selector
lever normally. Note:
If the indicator lamp blinks fast, one or more switching
conditions were not observed, or the LOW RANGE mode
is defective.

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Important!
During off-road driving a special low range system for
antilock brake system (ABS) and four-wheel electronic
traction system (4-ETS+) are operational with
transmission in the LOW RANGE mode.
In the low range mode the electronic stability program
(ESP) operates in a traction improving fashion
specifically adapted for off-road driving. At speeds
below 27 mph (45 km / h) the ESP assists in over- / understeering, thus improving vehicle tracking.
If one or more tires lose traction while driving downhill
(accelerator released), the 4-ETS+ engages and the
warning lamp v, located in the speedometer dial,
starts to f lash.
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. Notes:
Driving off or driving up to 3 mph (5 km / h) with the
service brakes applied lightly (to reduce drive wheel
spin), the 4-ETS+ remains engaged. Driving with the
service brakes applied lightly at vehicles speeds above
3 mph (5 km / h), the 4-ETS+ will not engage.
If the indicator lamp blinks fast, one or more switching
conditions were not observed, or the LOW RANGE mode
is defective.
In the case of a defective in the LOW RANGE mode the
transmission shifts in the usual manner. It is not
possible to switch on the LOW RANGE mode.
Have the transmission checked at your authorized
Mercedes-Benz Light Truck Center as soon as possible.

212
What you should know at the gas station
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What you should know at the gas station
Fuel supply Open f l ap by pu ll ing at rear (arrow). Turn f uel c ap to t he
left and hold on to it until possible pressure in tank has
been released, then remove cap. Failure to remove
slowly could result in personal injury.
The fuel filler cap is tethered to the fuel filler neck. Do
not drop the cap. It could damage the vehicle paint
finish.
Manual release of fuel filler flap, see page 274.
Important!
When refueling vehicle make certain that no gasoline
comes into contact with plastic taillamp, to prevent
damaging the lens.
Fuel
To prevent fuel vapors from escaping into open air, fully
insert filler nozzle unit.
Only fill fuel tank until the filler nozzle unit cuts out –
do not top up or overfill.
Wa r n i n g !
Gasoline is highly flammable and poisonous. It
burns violently and can cause serious injury.
Whenever you are around gasoline, avoid inhaling
fumes and skin contact, extinguish all smoking
materials. Never allow sparks, flame or smoking
materials near gasoline!

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What you should know at the gas station
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Leaving the engine running and the fuel cap open can
cause the “CHECK ENGINE” lamp to illuminate.
Fuel tank capacity approximately 19.0 US gal (72.0 l).
This includes approximately 3.2 US gal (12.0 l) reserve.
Use premium unleaded gasoline: Posted Octane
Index 91 (Average of 96 RON / 86 MON).
•Engine oil Engine oil level check, see page 89 and page 233.
Fill quantity between upper and lower dipstick
marking level: 2.1 US qt (2.0 l).
Recommended engine oils, see Approved Service
Products sheet. • Coolant
For normal replenishing, use water (potable water
quality).
For further information (e.g. anticorrosion/
antifreeze), see page 292.
• Spark plugs Approved spark plugs, see page 290.
• Tire pressure For tire pressure, refer to tire pressure label inside
the fuel filler flap. See page 250 for further details.
• Air conditioner R-134a refrigerant and special PAG lubricant, see
page 294.
Wa r n i n g !
Overfilling of fuel tank may result in creating
pressure in the system which could cause a gas
discharge such as the gas spraying back out upon
removing the filler nozzle which could cause
personal injury.