transmission MERCEDES-BENZ GLS SUV 2018 Manual PDF

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
!NThe yellow ABS warning lamp is lit while the engine is running.
ABS (Anti-lock Braking System) is deactivated due to a malfunction.
Other driving systems and driving safety systems may also malfunction.
In addition, the ÷andå warning lamps may light up in the instrument
cluster.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions listed
above. The wheels could therefore lock if you brake hard, for example.
The steerability and braking characteristics may be severely affected. The braking
distance in an emergency braking situation can increase.
If ESP
®is not operational, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XVisit a qualified specialist workshop immediately.
If the ABS control unit is faulty, there is also a possibility that other systems, such
as the navigation system or the automatic transmission, will not be available.
282Warning and indicator lamps in the instrument cluster
On-board computer and displays

Programming
Programming the buttons
Pay attention to the "Important safety notes"
(Ypage 321).
Garage door remote controlAis not included
with the integrated garage door opener.
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 140).
XSelect one of buttons ;to? to use to con-
trol the garage door drive.
XTo start programming mode: press and
hold one of buttons ;to? on the integrated
garage door opener.
The garage door opener is now in program-
ming mode. After a short time, indicator
lamp :lights up yellow.
Indicator lamp :lights up yellow as soon as
button ;,=or? is stored for the first time.
If the selected button has already been pro-
gramed, indicator lamp :will only light up
yellow after ten seconds have elapsed.
XRelease button ;,=or?. Indicator
lamp :flashes yellow.
XTo program the remote control: point
garage door remote control Atowards but-
tons ;to? on the rear-view mirror at a dis-
tance of 2 to 8 in (5 to 20 cm).
XPress and hold button Bon remote control
A until indicator lamp :lights up green.
When indicator lamp :lights up green: pro-
gramming is finished.
When indicator lamp :flashes green: pro-
gramming was successful. The next step is to synchronize the rolling code (
Ypage 322).
XRelease button Bon remote control Afor
the garage door drive system.
If indicator lamp :lights up red: repeat the
programing procedure for the corresponding
button on the rear-view mirror. When doing so, vary the distance between remote control
A
and the rear-view mirror.
The required distance between remote con-
trol Aand the integrated garage door opener
depends on the garage door drive system.
Several attempts might be necessary. You
should test every position for at least
25 seconds before trying another position.
Synchronizing the rolling code
Pay attention to the "Important safety notes"
(Ypage 321).
If the garage door system uses a rolling code,
you will also have to synchronize the garage
door system with the integrated garage door
opener in the rear-view mirror. To do this you will
need to use the programming button on the door
drive control panel. The programming button
may be located in different places depending on
the manufact

urer. It is usually located on the
door drive unit on the garage ceiling.
Familiarize yourself with the garage door drive
operating instructions, e.g. under "Program-
ming additional remote controls", before carry-
ing out the following steps.
Your vehicle must be within reach of the garage
door or gate opener drive. Make sure that nei-
ther your vehicle nor any persons/objects are
present within the sweep of the door or gate.
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 140).
XGet out of the vehicle.
XPress the programming button on the door
drive unit.
You now have 30 seconds to initiate the next
step.
XGet into the vehicle.
XPress previously programed button ;,=
or ? on the integrated garage door opener
repeatedly until the door closes.
The rolling code synchronization is then com- plete.
Notes on programming the remote con-
trol
Canadian radio frequency laws require a "break"(or interruption) of the transmission signals
after broadcasting for a few seconds. Therefore,
these signals may not last long enough for the
integrated garage door opener. The signal is not recognized during programming. Comparable
322Features
Stowage and features

with Canadian law, some U.S. garage door open-
ers also feature a "break".
Proceed as follows:
Rif you live in Canada.
Rif you have difficulties programming the
garage door opener (regardless of where youlive) when following the programming steps.
XPress and hold one of buttons ;to? on the
integrated garage door opener.
After a short time, indicator lamp :lights up
yellow.
XRelease the button.
Indicator lamp :flashes yellow.
XPress button Bof garage door remote con-
trol Afor two seconds, then release it for two
seconds.
XPress button Bagain for two seconds.
XRepeat this sequence on button Bof remote
control Auntil indicator lamp :lights up
green.
When indicator lamp :lights up green: pro-
gramming is finished.
When indicator lamp :flashes green: pro-
gramming was successful. The next step is to
synchronize the rolling code.
XRelease button Bof remote control Aof the
garage door drive.
When indicator lamp :lights up red: repeat
the programming process for the correspond-
ing button on the rear-view mirror. When
doing so, vary the distance between remote
control Aand the rear-view mirror.
The required distance between remote con-
trol Aand the integrated garage door opener
depends on the garage door drive system.
Several attempts might be necessary. You
should test every position for at least
25 seconds before trying another position.
Problems when programming
If you are experiencing problems programming
t
he integrated garage door opener on the rear-
view mirror, take note of the following instruc-
tions:
RCheck the transmitter frequency used by
garage door drive remote control Aand
whether it is supported. The transmitter fre-
quency can usually be found on the back of
remote control Afor the garage door drive.
The integrated garage door opener is com-
patible with devices that have units which operate in the frequency range of 280 to
433 MHz.
RReplace the batteries in garage door remote
control
A. This increases the likelihood that
garage door remote control Awill transmit a
strong and precise signal to the integrated
garage door opener.
RWhen programming, hold remote control A
at varying distances and angles from but-
tons ;to? which you are programming. Try
various angles at a distance between 2and
8 inches (5to 20 cm) or at the same angle but
at varying distances.
RIf a further remote control Ais available for
the same garage door drive, repeat the same
programming steps with this remote control
A. Before performing these steps, make sure
that new batteries have been installed in
garage door drive remote control A.
RNote that some remote controls only transmit
for a limited amount of time (the indicator
lamp on the remote control goes out). Press
buttonBon remote control Aagain before
transmission ends.
RAlign the antenna cable of the garage door
opener unit. This can improve signal recep-
tion/transmission.
Opening/closing the garage door
After it has been programmed, the integrated
garage door opener performs the function of the
garage door system remote control. Please also
read the operating instructions for the garage
door system.
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 140).
XPress button ;,=or? which you pro-
grammed to operate the garage door.
Garage door system with a fixed code: indi-
cator lamp :lights up green.
Garage door system with a rolling code: indi-
cator lamp :flashes green.
The transmitter will transmit a signal as long
as the button is pressed. The transmission is
halted after a maximum of ten seconds and
indicator lamp :lights up yellow.
XPress button ;,=or? again if necessary.
Features323
Stowage and features
Z

To avoid damage to the vehicle, deactivate
Distance Pilot DISTRONIC and the HOLD
function in the following or similar situations:
Rwhen towing the vehicle
Rin the car wash
!Never clean your vehicle in a Touchless
Automatic Car Wash as these use special
cleaning agents. These cleaning agents can
damage the paintwork or plastic parts.
!Make sure that:
Rthe side windows and the sliding sunroof
are fully closed.
Rthat the blower of the ventilation/heating
system is switched off (OFF button has
been pressed).
Rthe windshield wiper switch is at position
g.
The vehicle may otherwise be damaged.
!In car washes with a towing mechanism,
make sure that the automatic transmission is
in transmission position i; otherwise, the
vehicle could be damaged.
RVehicles with a SmartKey:
Do not remove the SmartKey from the igni-
tion lock. Do not open the driver's door or
front-passenger door when the engine is
switched off. Otherwise, the automatic
transmission selects park position jauto-
matically and locks the wheels. You can
prevent this by shifting the automatic trans-
mission to ibeforehand.
RVehicles with KEYLESS-GO:
Do not open the driver's door or front-
passenger door when the engine is
switched off. Otherwise, the automatic
transmission selects park position jauto-
matically and locks the wheels.
Observe the following to make sure that the
automatic transmission stays in position i:
XMake sure the vehicle is stationary and the
ignition is switched off.
XTurn the SmartKey to position in the ignition
lock2(Ypage 140).
Use the SmartKey instead of the Start/Stop
button on vehicles with KEYLESS-GO.
XDepress and hold the brake pedal.
XShift the automatic transmission to position
i.
XRelease the brake pedal.
XRelease the electric parking brake.
XSwitch off the ignition and leave the SmartKey
in the ignition lock.
You can wash the vehicle in an automatic car
wash from the very start.
If the vehicle is very dirty, pre-wash it before
cleaning it in an automatic car wash.
After using an automatic car wash, wipe off wax
from the windshield and the wiper blades. This
will prevent smears and reduce wiping noises caused by residue on t
he windshield.
Washing by hand
In some countries, washing by hand is only
allowed at specially equipped washing bays.
Observe the legal requirements in all countries
concerned.
XDo not use hot water and do not wash the
vehicle in direct sunlight.
XUse a soft sponge to clean.
XUse a mild cleaning agent, such as a car
shampoo approved by Mercedes-Benz.
XThoroughly hose down the vehicle with a gen-
tle jet of water.
XDo not point the water jet directly towards the
air inlets.
XUse plenty of water and rinse out the sponge
frequently.
XRinse the vehicle with clean water and dry
thoroughly with a chamois.
XDo not let the cleaning agent dry on the paint-
work.
When using the vehicle in winter, remove all
traces of road salt deposits carefully and as
soon as possible.
Power washers
GWARNING
The water jet from a circular jet nozzle (dirt
blasters) can cause invisible exterior damage
to the tires or chassis components. Compo-
nents damaged in this way may fail unexpect-
edly. There is a risk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced imme-
diately.
Care331
Maintenance and care
Z

the household rubbish. They
must be collected separatelyand recycled to protect the
environment.
Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
!Have the battery regularly checked at a
qualified specialist workshop.
For more information, please contact a quali-
fied specialist workshop.
!Always have work on batteries carried out at
a qualified specialist workshop.
Should it, in exceptional circumstances, be
absolutely necessary to disconnect the 12-
volt battery yourself, please observe the fol-
lowing:
RSecure the vehicle to prevent it from rolling
away.
RSwitch off the ignition.
RDisconnect the negative terminal first and
then the positive terminal.
The transmission is locked in position j
after disconnecting the battery.
After the work has been done, install the bat-
tery and replace the cover of the positive ter-
minal clamp firmly.
Comply with safety precautions and take pro-
tective measures when handling batteries.
Risk of explosion.
Fire, open flames and smoking are
prohibited when handling the bat-
tery. Avoid creating sparks.
Battery acid is caustic. Avoid contact
with skin, eyes or clothing.
Wear suitable protective clothing,
especially gloves, apron and face-
guard. Rinse any acid spills immediately
with clear water. Contact a physician
if necessary.
Wear eye protection.
Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehicle
occupants from suffering acid burns should the
battery be damaged in the event of an accident.
In order for the battery to achieve the maximum
possible service life, it must always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle.
In this case, have the battery disconnected at a
qualified specialist workshop. However, you can also charge the battery with a charger recom-
mended by Mercedes-Benz. Contact a qualified
specialist workshop for further information.
Have the battery condition of charge checked
more frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked for a long period of time.
Remove the SmartKey if you park the vehicle
and do not require any electrica l co
nsumers.
The vehicle will then use very little energy, thus conserving battery power.
If the power supply has been interrupted, e.g. if
you reconnect the battery, you will have to:
Rset the clock; see the Digital Operator's Man-
ual
On vehicles with a multimedia system and
navigation system, the clock is set automati-
cally.
Rreset the function for folding the exterior mir-
rors in/out automatically, by folding the mir-
rors out once (
Ypage 111)
Battery (vehicle)345
Breakdown assistance
Z

Make sure that:
RThe jumper cables are not damaged.
RBare parts of the terminal clamp do not come into contact with other metal parts while the jumpercables are connected to the battery.
RThe jumper cables cannot come into contact with parts which can move when the engine is
running, such as the V-belt pulley or the fan.
XSecure the vehicle by applying the electric parking brake.
XShift the transmission to position j.
XMake sure that the ignition is switched off. All indicator lamps in the instrument cluster must be
off. When using the SmartKey, turn the SmartKey to position uin the ignition lock and remove it
(
Ypage 140).
XSwitch off all electrical consumers, e.g. rear window defroster, lighting, etc.
XOpen the hood.
iRight-hand-drive vehicle: the jump-starting connection points may be located on the other
side of the vehicle.
Position number Bidentifies the charged battery of the other vehicle or an equivalent jump-starting
device.
XSlide cover :of positive terminal ;in the direction of the arrow.
XConnect positive terminal ;on your vehicle to positive terminal =of donor battery Busing the
jumper cable, always begin with positive terminal ;on your own vehicle first.
XStart the engine of the donor vehicle and run it at idling speed.
XConnect negative terminal ?of donor battery Bto ground point Aof your vehicle using the
jumper cable, beginning with donor battery Bfirst.
XStart the engine.
XBefore disconnecting the jumper cables, let the engine run for several minutes.
XFirst, remove the jumper cables from ground point Aand negative terminal ?, then from pos-
itive terminal ;and positive terminal =. Begin each time at the contacts on your own vehicle
first.
XClose cover :of positive terminal ;after removing the jumper cables.
XHave the battery checked at a qualified specialist workshop.
Jump-starting is not considered to be a normal operating condition.
348Jump-starting
Breakdown assistance

iJumper cables and further information regarding jump-starting can be obtained at any qualified
specialist workshop.
Towing and tow-starting
Important safety notes
GWARNING
Functions relevant to safety are restricted or
no longer available if:
Rthe engine is not running.
Rthe brake system or the power steering is
malfunctioning.
Rthere is a malfunction in the voltage supply or the vehicle's electrical system.
If your vehicle is being towed, much more
force may be necessary to steer or brake.
There is a risk of an accident.
In such cases, use a tow bar. Before towing,
make sure that the steering moves freely.
GWARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissible
gross weight of your vehicle, the:
Rthe towing eye could detach itself
Rthe vehicle/trailer combination could roll-
over.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per- missible gross weight of your vehicle.
Details on the permissible gross vehicle weight
of your vehicle can be found on the vehicle iden-
tification plate (
Ypage 385).
!When Active Brake Assist, Distance Pilot
DISTRONIC or the HOLD function is activated,
the vehicle brakes automatically in certain
situations.
To avoid damage to the vehicle, deactivate
these systems in the following or similar sit-
uations:
Rwhen towing the vehicle
Rin the car wash
!Make sure that the electric parking brake is
released. If the electric parking brake is faulty,
visit a qualified specialist workshop.
!Only secure the tow rope or tow bar at the
towing eyes, or the trailer tow hitch, if availa-
ble. You could otherwise damage the vehicle.
!Observe the following points when towing
with a tow rope:
RSecure the tow rope on the same side on
both vehicles.
RMake sure that the tow rope is not longer
than legally permitted. Mark the tow rope in
the middle, e.g. with a white c
loth
(11.8 x 11.8 in). This will make other road
users aware that a vehicle is being towed.
ROnly secure the tow cable to the towing
eyes or, if available, to the trailer tow hitch.
RObserve the brake lamps of the towing
vehicle while driving. Always maintain a dis-
tance a distance so that the tow rope does not sag.
RDo not use steel cables or chains to tow
your vehicle. You could otherwise damage
the vehicle.
!Do not use the trailer tow hitch for recovery
or towing. Do not use the towing eye for
recovery. this could damage the vehicle. If in
doubt, have the vehicle recovered using a
crane.
!When towing, pull away slowly and
smoothly. Pull the towed vehicle as straight as
possible and not at an acute angle. Excessive
tractive power could damage the vehicles.
When towing, it is preferable to use a rigid tow-
ing bar as opposed to a tow rope. A rigid towing bar helps to keep the tractive power low.
!When towing away vehicles with KEYLESS-
GO, use the key instead of the Start/Stop
button. The automatic transmission may oth-
erwise shift to position jwhen you open the
driver's or front-passenger door, which could
damage the transmission.
!Do not tow with sling-type equipment. This
could damage the vehicle.
Towing and tow-starting349
Breakdown assistance
Z

!Vehicles with differential locks: make sure
the differential locks are in automatic mode.
When towing, the differential locks must not
be switched on. The transmission may other-
wise be damaged.
!The vehicle can be towed a maximum of
30 miles (50km). The towing speed of 30 mph (50 km/h) must not be exceeded.
If the vehicle has to be towed more than
30 miles (50km), the entire vehicle must be
raised and transported.
It is better to have the vehicle transported than
to have it towed away.
If the vehicle has suffered transmission damage,
have it transported on a transporter or trailer.
The automatic transmission must be in position i when the vehicle is being towed.
The battery must be connected and charged.
Otherwise, you:
Rcannot turn the SmartKey to position 2in
the ignition lock
Rcannot release the electric parking brake
Rcannot shift the automatic transmission to
position i
Disarm the automatic locking feature before the
vehicle is towed (
Ypage 244). You could other-
wise be locked out when pushing or towing the
vehicle.
Installing/removing the towing eye
Installing the towing eye
The brackets for the screw-in towing eye are
located in the bumpers. They are at the front and
rear behind covers :;.
XRemove the towing eye from the vehicle tool
kit (Ypage 339).
XTo open the cover at the front: press the
mark on cover :inwards in the direction of
the arrow.
XTo open the cover at the rear: insert a flat,
blunt object into the cutout and lever
cover ;out of the bumper.
XTake cover :or; off the opening.
XScrew in the towing eye clockwise as far as it
will go and tighten it.
Removing the towing eye
XUnscrew and remove the towing eye.
XPosition cover :or; in the bumper and
press the cover on until it engages.
XPlace the towing eye in the vehicle tool kit.
Towing a vehicle with both axles on
the ground
The automatic transmission shifts to position
j automatically when you open the driver's or
front-passenger door or when you remove the
SmartKey from the ignition lock.
In order to ensure that the automatic transmis-
sion stays in position iwhen towing away the
vehicle, you must observe the following points:
XMake sure that the vehicle is stationary.
XTurn the SmartKey to position 2in the igni-
tion lock.
XDepress and hold the brake pedal.
XShift the automatic transmission to position
i.
XLeave the SmartKey in position 2in the igni-
tion lock.
XRelease the brake pedal.
XRelease the electric parking brake.
XSwitch on the hazard warning lamps
(Ypage 117).
In order to signal a change of direction when
towing the vehicle with the hazard warning
lamps switched on, use the combination switch
as usual. In this case, only the indicator lamps
for the direction of travel flash. After resetting
350Towing and tow-starting
Breakdown assistance

the combination switch, the hazard warning
lamp starts flashing again.
Transporting the vehicle
4MATIC vehicles/vehicles with auto-
matic transmission
!When the vehicle is loaded for transport, the
front and rear axles must be stationary and on
the same transportation vehicle. Positioning
over the connection point of the transport
vehicle is not permitted. The drive train may
otherwise be damaged.
All vehicles
!You may only secure the vehicle by the
wheels, not by parts of the vehicle such as
axle or steering components. Otherwise, the
vehicle could be damaged.
The towing eye can be used to pull the vehicle
onto a trailer or transporter for transporting pur-
poses.
XTurn the SmartKey to position 2in the igni-
tion lock.
XShift the automatic transmission to position
i.
As soon as the vehicle has been loaded:
XPrevent the vehicle from rolling away by
applying the electric parking brake.
XShift the automatic transmission to position
j.
XTurn the SmartKey to position uin the igni-
tion lock and remove it.
XSecure the vehicle.
Securing the vehicle
!After loading, the vehicle must be secured at
all four wheels. Otherwise, the vehicle could
be damaged.
A minimum distance of 8 in (20 cm) up and
4 in (10 cm) down must be maintained to the
transport platform.
XSecure all four wheels after loading the vehi-
cle.
Vehicles with ADS PLUS (Adaptive
Damping System PLUS)
Important safety notes
GWARNING
The weaker damping forces of the vehicle to
be transported can cause the vehicle/trailer
combination to swing.
As a result, when transporting vehicles with
Adaptive Damping System PLUS, the vehicle/
trailer combination may start to skid. Conse-
quently, you could lose control of the vehicle.
There is a risk of accident and injury.
When transporting, make sure that:
Rthe vehicle is has been loaded onto the
transporter correctly
Rthe vehicle is secured at all four wheels with
suitable tensioning straps
Ryou do not exceed the maximum permissi-
ble speed of 35 mph (60 km/h)
Securing the vehicle
!After loading, the vehicle must be secured at
all four wheels. Otherwise, the vehicle could
be damaged.
A minimum distance of 8 in (20 cm) up and
4 in (10 cm) down must be maintained to the
transport platform.
XSecure all four wheels after loading the vehi-
cle.
Information on 4MATIC vehicles
!
Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised, as
doing so will damage the transmission.
Towing and tow-starting351
Breakdown assistance
Z

Vehicles with 4MATIC may either be towed away
with both axles on the ground or be loaded up
and transported.
If the vehicle's transmission, front, or rear axle is
damaged, have the vehicle transported on a
truck or trailer.
In the event of damage to the electrical sys-
tem:if the battery is defective, the automatic
transmission will be locked in position P. To shift
the automatic transmission to position N, you
must provide power to the vehicle's electrical
system in the same way as when jump-starting
(
Ypage 346).
Have the vehicle transported on a transporter or
trailer.
Tow-starting (emergency engine
starting)
!
Vehicles with automatic transmission must
not be tow-started. You could otherwise dam-
age the automatic transmission.
You can find information on "Jump-starting"
under (
Ypage 346).
Fuses
Important safety notes
GWARNING
If you manipulate or bridge a faulty fuse or if
you replace it with a fuse with a higher amper- age, the electric cables could be overloaded.
This could result in a fire. There is a risk of an
accident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
!For the fuse boxes in the engine compart-
ment and under the rear bench seat, only use
fuses with the suffix "S". Otherwise, compo-
nents or systems could be damaged.
!Make sure that no moisture can enter the
fuse box when the cover is open.
!When closing the cover, make sure that it is
lying correctly on the fuse box. Moisture seep-
ing in or dirt could otherwise impair the oper-
ation of the fuses. The fuses in your vehicle serve to close down
faulty circuits. If a fuse blows, all the compo-
nents on the circuit and their functions stop
operating.
Blown fuses must be replaced with fuses of the
same rating, which you can recognize by the
color and value. The fuse ratings are listed in the
fuse allocation chart.
The fuse allocation chart is located in the fuse
box under the rear bench seat (
Ypage 353).
If a newly inserted fuse also blows, have the
cause traced and rectified at a qualified special-
ist workshop, e.g. an authorized Mercedes-Benz
Center.
Before changing a fuse
Observe the important safety notes
(Ypage 352)
XSwitch off the engine.
XSwitch off all electrical consumers.
XRemove the SmartKey from the ignition lock.
Or, on vehicles with KEYLESS-GO start function
or KEYLESS‑GO:
XOpen the driver's door.
The vehicle electronics are now in key posi-
tion u. This is the same as the SmartKey
having been removed.
The driver’s door can be closed again.
XSecure the vehicle against rolling away
(Ypage 161).
All indicator lamps in the instrument cluster
must be off.
The fuses are located in various fuse boxes:
RFuse box on the front-passenger side of the
dashboard
RFuse box in the engine compartment on the
right-hand side of the vehicle, when viewed in
the direction of travel
RFuse box under the rear bench seat
Dashboard fuse box
!
Do not use a pointed object such as a screw-
driver to open the cover in the dashboard. You
could damage the dashboard or the cover.
Mercedes-Benz recommends that you have this
work performed at a qualified specialist work-
352Fuses
Breakdown assistance