trailer MERCEDES-BENZ CLS COUPE 2014 Service Manual

Problem
Possible causes/consequences and
M
MSolutions J
The red brake system
warning lamp is lit while
the engine is running. A
warning tone also
sounds. There is insufficient brake fluid in the brake fluid reservoir.
G WARNING
Braking efficiency may be impaired.
There is a risk of an accident. X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 180).
X Do not top up the brake fluid. Topping up will not rectify the fault.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. !
The yellow ABS warning
lamp is lit while the
engine is running. ABS (Anti-lock Brake System) has been deactivated due to a fault.
Therefore, BAS (Brake Assist System), BAS PLUS, ESP ®
(Electronic
Stability Program), PRE ‑SAFE®
, PRE‑SAFE ®
Brake, the HOLD func-
tion, hill start assist, ESP ®
trailer stabilisation and the adaptive
brake lights, for example, are also deactivated.
ATTENTION ASSIST is deactivated.
G WARNING
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 affec-ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other systems, such as the navigation system or the automatic trans-
mission, will be unavailable. Warning and indicator lamps in the instrument cluster
289On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions !
The yellow ABS warning
lamp is lit while the
engine is running. ABS is temporarily unavailable. Therefore, BAS, BAS PLUS, ESP
®
,
EBD (electronic brake force distribution), PRE‑ SAFE®
,
PRE‑SAFE ®
Brake, the HOLD function, hill start assist, ESP ®
trailer
stabilisation and the adaptive brake lights, for example, are also
deactivated.
Possible causes:
R self-diagnosis is not yet complete
R the on-board voltage may be insufficient
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affec-ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is a risk of an accident.
X Carefully drive on a suitable stretch of road, making slight steer-
ing movements at a speed above 20 km/h.
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 290
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions !
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds. EBD is unavailable due to a malfunction. Therefore, ABS, BAS, BAS
PLUS, ESP ®
, PRE‑SAFE ®
, PRE‑SAFE ®
Brake, the HOLD function,
hill start assist, ESP ®
trailer stabilisation and the adaptive brake
lights, for example, are also unavailable.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affec-ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. J
֌!
The red brake warning
lamp, the yellow ESP ®
and ESP ®
OFF warning
lamps and the yellow
ABS warning lamp are
lit while the engine is
running. ABS and ESP
®
are unavailable due to a fault. Therefore, BAS, BAS
PLUS, EBD, PRE ‑SAFE®
, PRE‑SAFE ®
Brake, the HOLD function, hill
start assist, ESP ®
trailer stabilisation and the adaptive brake
lights, for example, are also unavailable.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affec-ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
291On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions ֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, BAS PLUS, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD
function, hill start assist, ESP ®
trailer stabilisation and the adap-
tive brake lights are unavailable due to a fault.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance may thus increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
293On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions ֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist and
ESP ®
trailer stabilisation are temporarily unavailable.
The adaptive brake lights, BAS PLUS and PRE‑SAFE ®
Brake may
also have failed.
ATTENTION ASSIST is deactivated.
Self-diagnosis is not yet complete.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance may thus increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Carefully drive on a suitable stretch of road, making slight steer-
ing movements at a speed above 20 km/h.
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 6
The red restraint sys-
tem warning lamp is lit
while the engine is run-
ning.
The restraint system is faulty.
G WARNING
The airbags or belt tensioners may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
This poses an increased risk of injury. X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Have the restraint system checked at a qualified specialist
workshop immediately.
For further information about the restraint system, see
(Y page 42). 294
Warning and indicator lamps in the instrument clusterOn-board computer and displays

vehicle and the high-pressure cleaner noz-
zle. Information about the correct distance is available from the equipment manufac-
turer. X
Clean sensors :of the driving systems
with water, car shampoo and a soft cloth.
Cleaning the reversing camera !
Do not clean the camera lens and the area
around the reversing camera with a high-
pressure cleaner. X
Use clear water and a soft cloth to clean
camera lens :.
Cleaning the exhaust tail pipes !
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 care product
tested and approved by Mercedes-Benz.
Cleaning the trailer tow hitch (CLS
Shooting Brake) H
Environmental note
Dispose of oily and greasy cloths in an envi-
ronmentally-responsible manner.
! Do not clean the ball coupling with a high-
pressure cleaner. Do not use solvents.
! 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, 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 :.
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. 338
CareMaintenance and care

X
First, remove the jump leads from earth point Aand negative terminal ?, then from pos-
itive clamp ;and positive terminal =. Begin each time at the contacts on your own vehicle
first.
X Close cover :of positive clamp ;after removing the jump leads.
X Have the battery checked at a qualified specialist workshop.
i Jump-starting is not considered to be a normal operating condition.
i Jump-starting cables and further information regarding jump starting can be obtained at
any qualified specialist workshop. Towing and tow-starting
Important safety notes
G
WARNING
Safety-relevant functions are restricted or not
available if:
R the engine is not running.
R the brake system or the power steering is
malfunctioning
R the voltage supply or the vehicle's electrical
system is malfunctioning.
If your vehicle is towed, significantly greater
force may be required to steer the vehicle or
to brake. There is a risk of an accident.
In such circumstances, use a towing bar.
Make sure that the steering is moving freely
before towing. G
WARNING
If the weight of the vehicle to be towed or tow- started is greater than the permissible gross
weight of your vehicle:
R the towing eye could detach itself
R the vehicle/trailer combination could over-
turn.
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.
i Information on your vehicle's gross vehi-
cle weight rating can be found on the vehi-
cle identification plate (Y page 398).!
If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automati-
cally in certain situations. To prevent dam-
age to the vehicle, deactivate DISTRONIC
PLUS and the HOLD function in the follow-
ing or other similar situations:
R when towing the vehicle
R in the car wash
! Only secure the tow cable or tow bar to
the towing eyes or, if available, to the trailer
tow hitch. You could otherwise damage the
vehicle.
! Observe the following points when towing
with a tow rope:
R Secure the tow rope on the same side on
both vehicles.
R Make sure that the tow rope is not longer
than legally permitted. Mark the tow rope
in the middle, e.g. with a white cloth
(30 x 30 cm). This will make other road
users aware that a vehicle is being
towed.
R Only secure the tow cable to the towing
eyes or, if available, to the trailer tow
hitch.
R Observe the brake lamps of the towing
vehicle while driving. Always maintain a
distance a distance so that the tow rope
does not sag.
R Do not use steel cables or chains to tow
your vehicle. You could otherwise dam-
age the vehicle. Towing and tow-starting
357Breakdown assistance Z

!
Do not use the towing eye for recovery,
this could damage the vehicle. If in doubt,
recover the vehicle with a crane.
! When towing, pull away slowly and
smoothly. If the tractive power is too high,
the vehicles could be damaged.
! To tow vehicles with KEYLESS-GO, use
the key instead of the Start/Stop button.
The automatic transmission may otherwise switch to position Pwhen you open the
driver's or front-passenger door which
could damage the transmission.
! You may tow the vehicle for a maximum of
50km. A towing speed of 50 km/h must not be exceeded.
For towing distances over 50 km, the entire
vehicle must be lifted up 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.
Observe the legal requirements for the rele-
vant countries when towing.
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 key in the ignition lock to
position 2
R cannot shift the automatic transmission to
position N
i Deactivate the automatic locking feature
before the vehicle is towed away
(Y page 90). You could otherwise be locked
out when pushing or towing the vehicle.
i Deactivate tow-away protection before
the vehicle is towed away (Y page 79). Fitting/removing the towing eye
Fitting the towing eye G
WARNING
The exhaust tail pipe may be extremely hot.
There is a risk of burning when removing the
rear cover.
Do not touch the exhaust tail pipe. Use
extreme caution when removing the rear
cover. Towing eye covers (example: CLS Coupé)
Towing eye covers (AMG vehicles)358
Towing and tow-startingBreakdown assistance

The towing eye can be used to pull the vehicle
onto a trailer or transporter for transporta-
tion.
The towing eyes or trailer tow hitch can be
used to pull the vehicle onto a trailer or trans-
porter if you wish to transport it.
X Turn the key to position 2in the ignition
lock.
X Shift the automatic transmission to posi-
tion N.
As soon as the vehicle is loaded:
X Prevent the vehicle from rolling away by
applying the parking brake.
X Shift the automatic transmission to posi-
tion P.
X Turn the key in the ignition lock to position
0 and remove the key from the ignition
lock.
X Secure the vehicle. Notes for 4MATIC vehicles
! Vehicles with 4MATIC must not be towed
with the front or rear axle raised; otherwise,
the transmission may be damaged.
If the vehicle has transmission damage or
damage to the front or rear axle, have it trans- ported on a transporter or trailer.
In the event of damage to the electrical
system
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 (Y page 355).
Have the vehicle transported on a transporter
or trailer. Tow-starting (emergency engine
starting)
! Vehicles with automatic transmission
must not be tow-started. The transmission
may otherwise be damaged.
i You can find information on "Jump-start-
ing" under (Y page 355). Electrical fuses
Important safety notes
G
WARNING
If you manipulate, bridge or replace a faulty
fuse with a fuse of a higher amperage, the
electric cables could be overloaded. This may result in a fire. There is a risk of an accident
and injury.
Always replace faulty fuses with specified new fuses of the correct amperage.
! Only use fuses that have been approved
for Mercedes-Benz vehicles and which
have the correct fuse rating for the system concerned. Otherwise, components or sys-
tems could be damaged.
The fuses in your vehicle serve to disconnect
faulty circuits. If a fuse blows, all the compo- nents on the circuit and their functions will
fail.
Blown fuses must be replaced with fuses of
the same rating, which you can recognise by
the colour and fuse rating. The fuse ratings
are listed in the fuse allocation chart.
If the newly inserted fuse also blows, have the
cause traced and rectified at a qualified spe-
cialist workshop, e.g. a Mercedes-Benz Ser-
vice Centre. Before replacing a fuse
Observe the important safety notes
(Y page 360) 360
Electrical fusesBreakdown assistance

Observe the recommended tyre pressures
and check the tyre pressure of all the tyres
including the spare wheel:
R every day before starting a journey
R when the load changes
R prior to long journey
R for changed operating conditions, e.g. off-
road driving
If necessary, correct the tyre pressure. G
WARNING
If you fit unsuitable accessories onto tyre
valves, the tyre valves may be overloaded and malfunction, which can cause tyre pressure
loss. Due to their design, retrofitted tyre pres-
sure monitors keep the tyre valve open. This
can also result in tyre pressure loss. There is a risk of accident.
Only screw standard valve caps or valve caps
specifically provided by Mercedes-Benz for
your vehicle onto the tyre valve. G
WARNING
If the tyre pressure drops repeatedly, the
wheel, valve or tyre may be damaged. Tyre
pressure that is too low may result in a tyre
blow-out. There is a risk of accident.
R Check the tyre for foreign objects.
R Check whether the wheel is losing air or the
valve is leaking.
If you are unable to rectify the damage, con-
tact a qualified specialist workshop. H
Environmental note
Check the tyre pressure regularly, at least
every 14 days.
You will find a table of tyre pressures for var- ious operating conditions on the inside of
your vehicle's fuel filler flap.
Operation with an emergency spare
wheel (Ypage 390).
Operation with a trailer: the applicable
value for the rear tyres is the maximum tyre pressure value stated in the table inside the
fuel filler flap.
The table inside the fuel filler flap may state
tyre pressures for different load conditions.
These are defined in the table as different
numbers of passengers and amounts of lug-
gage. The actual number of seats may vary;
for more information, please refer to the vehi-
cle's registration documents.
If tyre sizes are not specified, the tyre pres-
sures stated on the tyre pressure information
label apply for all tyres approved for this vehi- cle. If a tyre size precedes a tyre pressure, the
following tyre pressure information is only
valid for that tyre size.
Use a suitable pressure gauge to check the
tyre pressure. The outer appearance of a tyre does not permit any reliable conclusion aboutthe tyre pressure. On vehicles fitted with the
electronic tyre pressure monitor, the tyre
pressure can be checked using the on-board
computer.
If possible, only correct tyre pressures when
the tyres are cold.
The tyres are cold:
R if the vehicle has been parked with the tyres
out of direct sunlight for at least three
hours and
R if the vehicle has not been driven further
than 1.6 km
Depending on the ambient temperature, the
speed at which you are driving and the load on the tyres, the tyre temperature and thus the
tyre pressure changes by approximately 368
Tyre pressureWheels and tyres