ECU MERCEDES-BENZ B-Class 2017 W246 Manual Online

Tire-mounting tools should not be used near
the valve. This could damage the electronic
components.
Only have tires changed at a qualified spe-
cialist workshop.
Observe the instructions and safety notes in the "Changing a wheel" section (Y page 275).
The wear patterns on the front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before a clear wear pattern
has formed on the tires. Front tires typically
wear more on the shoulders and the rear tires in
the center.
On vehicles that have the same size front and
rear wheels, you can rotate the wheels accord-
ing to the intervals in the tire manufacturer's
warranty book in your vehicle documents. If no
warranty book is available, the tires should be
rotated every 3,000 to 6,000 miles (5,000 to
10,000 km). Depending on tire wear, this may
be required earlier. Do not change the direction
of wheel rotation.
Clean the contact surfaces of the wheel and the brake disc thoroughly every time a wheel is rota-
ted. Check the tire pressure and reactivate the
tire pressure monitor if necessary. Direction of rotation
Tires with a specified direction of rotation have
additional benefits, e.g. if there is a risk of hydro-
planing. These advantages can only be gained if the tires are installed corresponding to the
direction of rotation.
An arrow on the sidewall of the tire indicates its correct direction of rotation. Storing wheels
Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the tires
against oil and grease. Mounting a wheel
Preparing the vehicle X
Stop the vehicle on solid, non-slippery and
level ground.
X Apply the electric parking brake manually. X
Bring the front wheels into the straight-ahead
position.
X Shift the transmission to position P.
X Switch off the drive system.
X Vehicles without KEYLESS-GO: remove the
SmartKey from the ignition lock.
X Vehicles with KEYLESS-GO: open the driv-
er's door.
The vehicle electronics now have status 0.
This is the same as the SmartKey having been removed.
X If included in the vehicle equipment, remove
the tire-change tool kit from the vehicle.
X Safeguard the vehicle against rolling away
(Y page 128).
Securing the vehicle to prevent it from
rolling away If your vehicle is equipped with a wheel chock, it
can be found in the tire-change tool kit
(Y page 241).
The folding wheel chock is an additional safety
measure to prevent the vehicle from rolling
away, for example when changing a wheel.
X Fold both plates upwards 0043.
X Fold out lower plate 0044.
X Guide the lugs on the lower plate fully into the
openings in base plate 0087.276
Changing a wheelWheels and tires

X
Place chocks or other suitable items under
the front and rear of the wheel that is diago-
nally opposite the wheel you wish to change.
Raising the vehicle G
WARNING
If you do not position the jack correctly at the appropriate jacking point of the vehicle, the
jack could tip over with the vehicle raised.
There is a risk of injury.
Only position the jack at the appropriate jack-
ing point of the vehicle. The base of the jack
must be positioned vertically, directly under
the jacking point of the vehicle.
! Position a suitable jack correctly on the
intended jacking points. If you fail to position the jack correctly, the vehicle may be dam-
aged.
The jacking points are recesses in the lower
door sill. They can only be seen from under-
neath. There is one located behind each of the
front wheel arches and in front of the rear
wheel arches.
Position the jack in the jacking points so that when viewed from the side, the jack is in the
vertical position.
! Position a suitable jack only on the jacking
points intended for this purpose.
Never position the jack on the high-voltage
battery. Do not jack up the vehicle on the
high-voltage battery. There is otherwise a risk of damaging the high-voltage battery.
Also observe the notes in the "Changing a
wheel" section. Observe the following when raising the vehi-
cle:
R To raise the vehicle, only use the vehicle-spe-
cific jack that has been tested and approved
by Mercedes-Benz. If used incorrectly, the
jack could tip over with the vehicle raised.
R The jack is designed only to raise and hold the
vehicle for a short time while a wheel is being
changed. It must not be used for performing
maintenance work under the vehicle.
R Avoid changing the wheel on uphill and down-
hill slopes.
R Before raising the vehicle, secure it from roll-
ing away by applying the parking brake and
inserting wheel chocks. Do not disengage the
parking brake while the vehicle is raised.
R The jack must be placed on a firm, flat and
non-slip surface. On a loose surface, a large,
flat, load-bearing underlay must be used. On a
slippery surface, a non-slip underlay must be
used, e.g. rubber mats.
R Do not use wooden blocks or similar objects
as a jack underlay. Otherwise, the jack will not
be able to achieve its load-bearing capacity
due to the restricted height.
R Make sure that the distance between the
underside of the tires and the ground does not
exceed 1.2 in (3 cm).
R Never place your hands and feet under the
raised vehicle.
R Do not lie under the vehicle.
R Do not start the drive system when the vehicle
is raised.
R Never open or close a door or the tailgate
when the vehicle is raised.
R Make sure that no persons are present in the
vehicle when the vehicle is raised. Changing a wheel
277Wheels and tires Z

X
Using lug wrench 0043, loosen the bolts on the
wheel you wish to change by about one full
turn. Do not unscrew the bolts completely. Jacking points
The jacking points are located just behind the
front wheel housings and just in front of the rear wheel housings (arrows). X
Take ratchet wrench 0085out of the vehicle tool
kit and place it on the hexagon nut of jack 0087
so that the letters AUFare visible.
X Position jack 0087at jacking point 0044. X
Make sure the foot of the jack is directly
beneath the jacking point. X
Turn ratchet wrench 0085until jack 0087sits
completely on jacking point 0044and the base
of the jack lies evenly on the ground.
X Turn ratchet wrench 0085until the tire is raised
a maximum of 1.2 in (3 cm) from the ground.
Removing a wheel !
Do not place wheel bolts in sand or on a dirty
surface. The bolt and wheel hub threads could
otherwise be damaged when you screw them
in.
X Unscrew the wheel bolts.
X Remove the wheel.
Mounting a new wheel G
WARNING
Oiled or greased wheel bolts or damaged
wheel bolts/hub threads can cause the wheel bolts to come loose. As a result, you could
lose a wheel while driving. There is a risk of
accident.
Never oil or grease wheel bolts. In the event ofdamage to the threads, contact a qualified
specialist workshop immediately. Have the
damaged wheel bolts or hub threads
replaced/renewed. Do not continue driving. G
WARNING
If you tighten the wheel bolts or wheel nuts
when the vehicle is raised, the jack could tip
over. There is a risk of injury.
Only tighten the wheel bolts or wheel nuts
when the vehicle is on the ground.
Always pay attention to the instructions and
safety notes in the "Changing a wheel" section
(Y page 275).
Only use wheel bolts that have been designed
for the wheel and the vehicle. For safety rea-
sons, Mercedes-Benz recommends that you
only use wheel bolts which have been approved for Mercedes-Benz vehicles and the respective
wheel.
! To prevent damage to the paintwork, hold
the wheel securely against the wheel hub
while screwing in the first wheel bolt. 278
Changing a wheelWheels and tires