trailer hitch MERCEDES-BENZ M-Class 2015 W166 User Guide

Ball coupling recess
Holes in the ball coupling and ball coupling recess
X Insert the ball coupling horizontally into ball
coupling recess 0044in the direction of the
arrow until the holes in ball coupling 0087are
in line with the holes in ball coupling
recess 0085. Bolt
X Slide bolt 0083into the hole in the ball cou-
pling recess and the ball coupling to the
stop. Bolt and spring cotter
X Secure the bolt using spring cotter 0084. Correctly installed and secured ball coupling
X Check the ball coupling, bolt and spring
cotter for correct installation.
If the ball coupling cannot be correctly moun-
ted, remove the ball coupling. Under these
circumstances, the ball coupling must not be used for trailer towing.
If the ball coupling cannot be locked and the
key cannot be removed, remove the ball cou-
pling and clean it. If the ball coupling can still
not be installed (locked) after it has been
cleaned, remove the ball coupling. The trailer tow hitch must then not be used to tow a
trailer, as safe operation cannot be guaran-
teed.
Have the entire trailer tow hitch checked at aqualified specialist workshop. Coupling up a trailer
! Do not connect the trailer's brake system
(if featured) to the hydraulic brake system Towing a trailer
259Driving and parking Z

of the towing vehicle, as the latter is equip-
ped with an anti-lock brake system. Doing
so will result in a loss of function of the
brake systems of both the vehicle and the
trailer.
X Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's electric parking brake.
X Start the engine.
X Vehicles with the AIRMATIC package:
select highway level.
X Vehicles with ADS: set ADS toAUTOor
COMF.
X Switch off the engine.
X Close all doors and the tailgate.
X Couple up the trailer.
X Establish all electrical connections.
X Check that the trailer lighting system is
working.
i Vehicles with the AIRMATIC package:
with a trailer attached, the vehicle will
always remain at highway level. When cou-
pling up a trailer, please observe the fol-
lowing:
R Unless highway level has been set man-
ually, the vehicle is automatically low-
ered to highway level. This is the case if a
speed of 5 mph (8 km/h) is reached.
R High-speed level is not available.
These restrictions apply to all accessories
powered through a connection to the trailer power socket of your vehicle, e.g. a bicycle
carrier.
Observe the maximum permissible trailer
dimensions (width and length).
Most U.S. states and all Canadian provinces
require by law:
R Safety chains between the towing vehicle
and the trailer. The chains should be cross-
wound under the trailer drawbar. They must be fastened to the vehicle's trailer cou-
pling, not to the bumper or the axle. Leave enough play in the chains to make
tight cornering possible.
R A separate brake system for certain types
of trailer.
R A safety switch for braked trailers. Check
the specific legal requirements applicable
to your state.
If the trailer detaches from the towing vehi- cle, the safety switch applies the trailer's
brakes. Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed
restrictions. Make sure that your car/trailer
combination complies with the local regula-
tions: R in your place of residence
R in the location to which you are driving
The police and local authorities can provide
reliable information.
Observe the following when towing a trailer:
R To gain driving experience and to become
accustomed to the new handling charac-
teristics, you should practice the following
in a traffic-free location:
- cornering
- stopping
- backing up
R Before driving, check:
- trailer tow hitch
- safety switch for braked trailers
- safety chains
- electrical connections
- lights
- wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the trailer.
R If the trailer has electronically controlled
brakes, pull away carefully. Brake manually 260
Towing a trailerDriving and parking

X
Detach the trailer cable and decouple the
trailer.
X Switch off the engine. Permissible trailer loads and drawbar
loads
Weight specifications Maximum permissible gross vehicle
weight rating
The gross trailer weight is calculated by add-
ing the weight of the trailer to the weight of
the load and equipment on the trailer.
You will find installing dimensions and loads
under "Technical data" (Y page 459).
Permissible noseweight
You will find installing dimensions and loads
under "Technical data" (Y page 459).
Loading a trailer R
When loading the trailer, make sure that
neither the permissible gross weight of the
trailer nor the gross vehicle weight is
exceeded. The permissible gross vehicle
weight is indicated on the identification
plate on the B-pillar on the driver's side of
the vehicle.
You can find the maximum permissible val-
ues on the type plates of your vehicle and
the trailer. When calculating how much
weight the vehicle and trailer may carry,
pay attention to the respective lowest val-
ues.
R The trailer drawbar load on the ball coupling
must be added to the rear axle load to avoid exceeding the permissible gross axle
weight. The permissible gross vehicle
weight is indicated on the identification
plate on the B-pillar on the driver's side of
the vehicle.
i Mercedes-Benz recommends a trailer
load where the trailer drawbar noseweight accounts for 8% to 15% of the trailer's per-
missible gross weight.
i The weight of additional accessories, pas-
sengers, and cargo reduces the permissi-
ble trailer load and drawbar load for your
vehicle.
Checking the vehicle and trailer weight R
To check that the weights of the towing
vehicle and the trailer comply with the max-
imum permissible values, have the vehicle/
trailer combination (including the driver,
passengers, and cargo with a fully laden
trailer) weighed on a calibrated weigh-
bridge.
R Check the gross axle weight rating of the
front and rear axles, the gross weight of the
trailer and trailer drawbar load. Removing the ball coupling
X Remove the spring cotter.
X Remove the bolt from the ball coupling
recess.
X Remove the ball coupling from the ball cou-
pling recess.
X Clean the ball coupling if it is dirty.
X Stow the ball coupling so that it cannot be
thrown around.
Observe the loading guidelines (Y page 334)
and the safety notes regarding stowage
spaces (Y page 335).
Information on cleaning and care of the trailer tow hitch can be found at (Y page 376). Storing the ball coupling
G
WARNING
Do not carry the ball coupling in the vehicle
interior if it is not secured.
Otherwise, you and others could be injured by the ball coupling being thrown around if you: 262
Towing a trailerDriving an
d parking

Display messages
Possible causes/consequences and
0050
0050Solutions 0049
Check Front Left Check Front Left
Parking Lamp Parking Lamp
or
Check Front Right
Check Front Right
Parking Lamp Parking Lamp The front left or front right parking or standing lamp is defective.
X Check whether you are permitted to replace the bulb yourself
(Y page 129).
or
X Visit a qualified specialist workshop. 0049
Backup Light Backup Light The backup lamp is defective.
X Visit a qualified specialist workshop. 0049
Check Front Left Check Front Left
Sidemarker Lamp Sidemarker Lamp
or
Check Front Right
Check Front Right
Sidemarker Lamp Sidemarker Lamp The left or right front side marker lamp is defective.
X Visit a qualified specialist workshop. 0049
Check Left Tail Check Left Tail
Lamp Lamp
orCheck
Check
Right Tail Lamp
Right Tail Lamp The left or right-hand tail lamp is defective.
or
The rear left or right side marker lamp is defective.
X Visit a qualified specialist workshop. 0049
Check Check
Left
LeftDaytime
Daytime
Running Light
Running Light or
Check Right Day‐
Check Right Day‐
time Running Light time Running Light The left-hand or right-hand daytime running lamp is faulty.
X Visit a qualified specialist workshop. 0049
Active Light Sys‐ Active Light Sys‐
tem Inoperative tem Inoperative The active light function is defective.
X Visit a qualified specialist workshop. 0049
Malfunction See Malfunction See
Operator's Manual Operator's Manual The exterior lighting is defective.
X Visit a qualified specialist workshop. Vehicles with trailer tow hitch: a fuse may have blown.
X Check the fuses (Y page 396).
X If necessary, replace the blown fuse. Observe the warning notes.
If the display message continues to be displayed: X Visit a qualified specialist workshop. Display
messages
299On-board computer and displays Z

the vehicle and the power washer nozzle.
Information about the correct distance is
available from the equipment manufac-
turer. X
Clean sensors 0043of the driving systems
with water, car shampoo and a soft cloth.
Cleaning the rear view camera !
Do not clean the camera lens and the area
around the rear view camera with a power
washer. X
Use clear water and a soft cloth to clean
camera lens 0043.
Cleaning the 360° camera !
Do not clean the camera lens and the area
around the 360° camera with a power
washer.360 X
Use clear water and a soft cloth to clean
camera lens 0043.
Cleaning the exhaust pipe G
WARNING
The exhaust tail pipe and tail pipe trim can
become very hot. If you come into contact
with these parts of the vehicle, you could burn
yourself. There is a risk of injury.
Always be particularly careful around the
exhaust tail pipe and the tail pipe trim. Allow
these components to cool down before touch-
ing them.
! Do not clean the exhaust pipe with acid-
based cleaning agents such as sanitary
cleansers or wheel cleaners.
Impurities combined with the effects of road
grit and corrosive environmental factors may cause flash rust to form on the surface. You
can restore the original shine of the exhaust
pipe by cleaning it regularly, especially in win- ter and after washing.
X Clean the exhaust pipe with a chrome care
product tested and approved by Mercedes-
Benz.
Cleaning the trailer tow hitch H
Environmental note
Dispose of rags soaked in oil and grease in an environmentally responsible manner.
! Do not clean the ball coupling with a
power washer. Do not use solvents. 376
CareMaintenance and care

!
Please note the care instructions in the
trailer coupling manufacturer's operating
instructions. The ball coupling must be cleaned if it
becomes dirty or corroded.
X Remove rust on the ball of the ball coupling,
e.g. with a wire brush.
X Remove dirt with a clean, lint-free cloth or a
brush.
X After cleaning, lightly oil or grease ball cou-
pling 0043.
X Check that the vehicle's trailer tow hitch is
working properly.
i You can also have the maintenance work
on the ball coupling and the trailer tow hitch
carried out by a qualified specialist work-
shop. Interior care
Cleaning the display !
For cleaning, do not use any of the fol-
lowing:
R alcohol-based thinner or gasoline
R abrasive cleaning agents
R commercially-available household clean-
ing agents
These may damage the display surface. Do not put pressure on the display surface
when cleaning. This could lead to irrepara-
ble damage to the display. X
Before cleaning the display, make sure that
it is switched off and has cooled down.
X Clean the display surface using a commer-
cially available microfiber cloth and
TFT/LCD display cleaner.
X Dry the display surface using a dry micro-
fiber cloth.
Cleaning Night View Assist Plus !
Never clean the camera lens. When clean-
ing the field of vision of the driving systems, make sure that you do not spray glass
cleaner on the camera lens. If the camera
lens is dirty, visit a qualified specialist work-
shop. X
Fold down the camera cover by recess 0043. X
Use a soft cloth to clean the windshield in
front of camera 0044. Care
377Maintenance and care Z

Useful information
i This Operator's Manual describes all
models and all standard and optional equip- ment of your vehicle available at the time of
publication of the Operator's Manual.
Country-specific differences are possible.
Please note that your vehicle may not be
equipped with all features described. This
also applies to safety-related systems and
functions.
i Read the information on qualified special-
ist workshops (Y page 29). Where will I find...?
Vehicle tool kit
General notes The vehicle tool kit can be found in the stow-
age well under the cargo compartment floor.
i Apart from certain country-specific varia-
tions, the vehicles are not equipped with a
tire-change tool kit. Some tools for chang-
ing a wheel are specific to the vehicle. For
more information on which tools are
required to perform a wheel change on your vehicle, consult a qualified specialist work-
shop.
Tools required for changing a wheel may
include, for example:
R Jack
R Wheel chock
R Lug wrench
R Ratchet wrench
R Alignment bolt Vehicles with a TIREFIT kit Vehicle tool kit (example)
0043
Lug wrench
0044 Jack
0087 Alignment bolt
0085 Tire inflation compressor
0083 Tire sealant filler bottle
0084 Folding wheel chock
006B Towing eye
006C Ratchet wrench
Use the TIREFIT kit (Y page 384).
Vehicles with a "Minispare" emergency
spare wheel Example: vehicles with AIRMATIC and trailer tow
hitch
0043
Folding wheel chock
0044 Lug wrench
0087 Alignment bolt
0085 Towing eye
0083 Jack
0084 Ratchet wrench 382
Where will I find...?Breakdown assistance

!
Only secure the tow rope or tow bar at the
towing eyes. Otherwise, the vehicle could
be damaged.
! Do not use the trailer tow hitch for recov-
ery 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.
i When towing, it is preferable to use a rigid
towing bar as opposed to a tow rope. A rigid
towing bar helps to keep the tractive power low.
! When towing vehicles with KEYLESS-GO,
use the key instead of the Start/Stop but-
ton. Otherwise, the automatic transmission
may shift to position Pwhen the driver's or
front-passenger door are opened, which
could lead to damage to the transmission.
! Do not tow with sling-type equipment.
This could damage the vehicle.
! 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 otherwise 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.
! If you tow or tow-start another vehicle, its
weight must not exceed the maximum per- missible gross vehicle weight of your vehi-
cle.
i Information on your vehicle's gross vehi-
cle weight rating can be found on the vehi-
cle identification plate (Y page 446).It is better to have the vehicle transported
than to have it towed.
If the vehicle has suffered transmission dam-
age, have it transported on a transporter or
trailer.
The automatic transmission must be in posi-
tion Nwhen the vehicle is being towed.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the SmartKey to position 2in
the ignition lock
R cannot release the electric parking brake
R cannot shift the automatic transmission to
position N
i Disarm the automatic locking feature
before the vehicle is towed (Y page 279).
You could otherwise be locked out when
pushing or towing the vehicle. Installing/removing the towing eye
Installing the towing eye Example: towing eye mounting covers
0043 Front cover
0044 Back cover
The brackets for the screw-in towing eyes are
located in the bumpers. They are at the front and at the rear, behind the covers. 394
Towing and tow-startingBreakdown assistance

the tire. This specifies the load-bearing capa-
city more precisely.
Curb weight
The weight of a vehicle with standard equip-
ment including the maximum capacity of fuel,
oil and coolant. It also includes the air-condi- tioning system and optional equipment if
these are installed in the vehicle, but does notinclude passengers or luggage.
Maximum load rating
The maximum tire load is the maximum per-
missible weight in kilograms or lbs for which a
tire is approved.
Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire.
Maximum load on one tire
Maximum load on one tire. This is calculated
by dividing the maximum axle load of one axle
by two.
PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire
width in percent.
Tire pressure
This is pressure inside the tire applying an
outward force to each square inch of the tire's surface. The tire pressure is specified in
pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold.
Cold tire pressure
The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has been driven for less than
1 mile (1.6 km). Tread
The part of the tire that comes into contact
with the road.
Bead
The tire bead ensures that the tire sits
securely on the wheel. There are several steel
wires in the bead to prevent the tire from
coming loose from the wheel rim.
Sidewall
The part of the tire between the tread and the bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kilograms (5 lbs).
These optional extras, such as high-perform-
ance brakes, level control, a roof rack or a
high-performance battery, are not included in the curb weight and the weight of the acces-
sories.
TIN (Tire Identification Number)
This is a unique identifier which can be used
by a tire manufacturer to identify tires, for
example for a product recall, and thus identify
the purchasers. The TIN is made up of the
manufacturer's identity code, tire size, tire
type code and the manufacturing date.
Load bearing index
The load bearing index (also load index) is a
code that contains the maximum load bearing capacity of a tire.
Traction
Traction is the result of friction between the
tires and the road surface.
TWR (Tongue Weight Rating)
The TWR specifies the maximum permissible
weight that the ball coupling of the trailer tow
hitch can support. 422
All about
wheels and tiresWheels and tires

!
AMG vehicles with "Minispare" emer-
gency spare wheel: use the "Minispare"
emergency spare wheel only on the rear
axle. If you mount the "Minispare" emer-
gency spare wheel on the front axle, this
could result in damage to the brake system.
If a tire on the front axle is defective, an
intact wheel from the rear axle must first be
replaced with the "Minispare" emergency
spare wheel. The defective wheel on the
front axle can then be replaced with the
intact wheel from the rear axle.
Make sure to note the placard on the
"Minispare" emergency spare wheel.
When using an emergency spare wheel or
spare wheel of a different size, you must not
exceed the maximum speed of 50 mph
(80 km/h).
Snow chains must not be mounted on emer-
gency spare wheels. General notes
Mounting the emergency spare wheel is
described under "Mounting a wheel"
(Y page 424).
You should regularly check the pressure of
the emergency spare wheel, particularly prior
to long trips, and correct the pressure as nec-
essary (Y page 404). The value on the wheel
or as given in the "Wheels and tires" section is
valid (Y page 443).
An emergency spare wheel may also be
mounted against the direction of rotation.
Observe the time restriction on use as well as
the speed limitation specified on the emer-
gency spare wheel.
Replace the tires after six years at the latest, regardless of wear. This also applies to the
emergency spare wheel.
i When you are driving with the collapsible
spare wheel mounted, the tire pressure
loss warning system or the tire pressure
monitor cannot function reliably. Only
restart the tire pressure loss warning sys- tem/the tire pressure monitor when the
damaged wheel has been replaced with a
new wheel.
Vehicles with tire pressure monitor:
after mounting an emergency spare wheel,
the system may still display the tire pres-
sure of the removed wheel for a few
minutes. The value displayed for the moun-
ted emergency spare wheel is not the same as the current tire pressure of the emer-
gency spare wheel. Removing the emergency spare wheel
Emergency spare wheel (example: vehicle without
lockable cargo compartment floor)
The "Minispare" emergency spare wheel can
be found in the stowage well under the cargo
compartment floor.
X Lift the cargo compartment floor up
(Y page 344).
X Vehicles with trailer tow hitch: remove
the ball coupling stowage tray
(Y page 258).
X Vehicles without a lockable cargo com-
partment floor: turn emergency spare
wheel retainer 0044counter-clockwise and
remove it.
X Remove "Minispare" emergency spare
wheel 0043. Emergency spare wheel
441Wheels and tires Z