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Display messages
237Display messages Possible cause/consequence Possible solution
N Check engine oil
level when next
refuelling The engine oil level has dropped to a crit-
ical level. X
Check the engine oil level (Y page 195) and top
up the engine oil if necessary.
X Have the engine checked for leaks if the engine
oil needs topping up more often than usual. ± Display malfunc-
tion Consult work-
shop One or more electronic systems are
unable to deliver information to the on-
board computer. The following systems
may have failed:
R
Coolant temperature gauge
R Rev counter
R Cruise control or Speedtronic display X
Visit a qualified specialist workshop. H Tyre pressure Cau-
tion Tyre defect One or more tyres are losing air rapidly.
The affected wheel is highlighted in the
tyre pressure display of the tyre pressure
monitor*. X
Stop the vehicle without making any sudden
steering
or braking manoeuvres. Pay attention
to the traffic conditions as you do so.
X Repair or change the tyre (Y page 276). Practical advice
* optional
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Display messages
238 Display messages Possible cause/consequence Possible solution
H Tyre pressure
Check tyres The pressure in one or more tyres has
dropped significantly. The affected wheel
is highlighted in the tyre pressure display
of the tyre pressure monitor*. X
Stop the vehicle without making any sudden
steering
or braking manoeuvres. Pay attention
to the traffic conditions as you do so.
X Check the tyres.
X Repair or change the faulty tyre if necessary
(Y page 276).
X Check the tyre pressure and correct it if nec-
essary ( Y page 200).
The warning will disappear automatically after
you have been driving for a few minutes with
the corrected tyre pressure. I Change key batter-
ies
The batteries of the KEYLESS GO key* are
discharged. X
Change the batteries ( Y page 269).I Key not detected
The KEYLESS GO key* is not in the vehicle.
It will no longer be possible to centrally
lock
the vehicle and start the engine if the
engine is switched off. X
Stop the vehicle. Pay attention to the traffic
conditions as you do so.
X Look for the KEYLESS GO key*. I Key not detected
The KEYLESS GO * key is not detected
while
the engine is running, because there
is interference from a strong source of
radio waves. X
Stop the vehicle. Pay attention to the traffic
conditions as you do so.
X Operate the vehicle using the key in the ignition
lock if necessary. Practical advice
* optional
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Display messages
239Display messages Possible cause/consequence Possible solution
I Key not detected
The KEYLESS GO key* cannot be detected
at present. X
Change the location of the KEYLESS GO key*
within the vehicle.
X Operate the vehicle using the key in the ignition
lock if necessary. I Key still in vehi-
cle
The KEYLESS GO key* was detected
inside the vehicle during locking. X
Remove the KEYLESS GO key* from the vehi-
cle. I Please replace key The key no longer functions. X
Visit a qualified specialist workshop. X inoperative Bat-
tery weak The battery voltage is insufficient. The
auxiliary heating/ventilation*
has
switched off or cannot be switched on. X
Drive for a longer distance.
The battery is being charged. The auxiliary
heating/ventilation* is reactivated as soon as
there is sufficient battery voltage. X inoperative Refuel There is insufficient fuel in the fuel tank.
The
auxiliary heating* cannot be switched
on. X
Refuel at the nearest filling station. X inoperative See
Owner's Manual
The auxiliary heating* has a temporary
malfunction or is faulty. X
When the vehicle is on a level surface and the
engine has cooled down: try to switch on the
auxiliary heating*
four times, waiting for sev-
eral minutes between each attempt.
X If the auxiliary heating* does not switch on:
visit a qualified specialist workshop. Practical advice
* optional
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Display messages
240 Display messages Possible cause/consequence Possible solution
W Reserve fuel level The fuel level has fallen below the reserve
range.
The operation of the auxiliary heat-
ing* can no longer be guaranteed. X
Refuel at the nearest filling station. t Enter PIN: You have not yet logged on to your mobile
phone*. X
Enter the PIN for the SIM card. t Bluetooth ready The Bluetooth connection between your
mobile phone and the audio system or
COMAND APS*
is not activated. X
The Bluetooth connection between your
mobile phone and the audio system or
COMAND APS*
is not activated, see separate
operating instructions. t No telephone
inserted Your mobile phone is not inserted in the
bracket*. X
Insert mobile phone into the bracket*
(Y page 183). W Top up washer fluid The washer fluid level in the washer fluid
reservoir has dropped below the mini-
mum. X
Top up the washer fluid ( Y page 197).Practical advice
* optional
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Troubleshooting
244 Indicator and warning lamps in the instrument cluster
Problem Possible cause/consequence Suggested solutions
-
The yellow ABS warning
lamp comes on while the
engine is running. G
Risk of accident
ABS is unavailable due to a mal-
function. Therefore, Brake Assist,
ESP ®
, EBV and PRE-SAFE ®
are,
for example, also deactivated.
The brake system continues to
function normally, but without
electronic support. The wheels
could therefore lock if you brake
hard, for example. X
Drive on carefully.
X Observe the additional messages in the multi-function display
(Y page 219).
X Visit a qualified specialist workshop as soon as possible. v
The yellow ESP ®
warning
lamp
is lit while the engine
is running. G
Risk of accident
ESP ®
is deactivated. ESP ®
will
not
stabilise the vehicle if it starts
to skid or if a wheel starts to spin. X
Reactivate ESP ®
(Y page 59).
Exceptions:
(Y page 59).
X Adapt your driving style to suit the road and weather conditions. v
The yellow ESP ®
warning
lamp
is lit while the engine
is running. G
Risk of accident
ESP ®
is unavailable due to a mal-
function. ESP ®
will not stabilise
the vehicle if it starts to skid or if
a wheel starts to spin. X
Observe the additional messages in the multi-function display
(Y page 220).
X Drive on carefully.
X Visit a qualified specialist workshop. Practical advice
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Troubleshooting
245Problem Possible cause/consequence Suggested solutions
v
The yellow ESP ®
warning
lamp flashes while the
vehicle is in motion. G
Risk of accident
ESP ®
or traction control has
intervened because at least one
wheel has started to spin.
Cruise control or Distronic* is
deactivated. X
Only depress the accelerator pedal as far as necessary when pull-
ing away.
X Release the accelerator pedal while you are driving.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
. Exceptions: (Y page 59).3
The red brake system
warning lamp comes on
while you are driving. You
will also hear a warning
tone. You are driving with the parking
brake applied. X
Release the parking brake.
The warning lamp goes out and the warning tone ceases. 3
The red brake system
warning lamp comes on
while the engine is run-
ning. You will also hear a
warning tone. G
Risk of accident
There is insufficient brake fluid in
the fluid reservoir. X
Do not continue driving under any circumstances.
X Consult a qualified specialist workshop immediately.
X Observe the additional messages in the multi-function display
(Y page 219).
X Under no circumstances should you top up the brake fluid. This will
not rectify the fault. l
The red distance warning
lamp* lights up while the
vehicle is in motion. G
Risk of accident
The distance to the vehicle in
front is too short for the speed
selected. X
Increase the distance. Practical advice
* optional
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Troubleshooting
248 Problem Possible cause/consequence Suggested solutions
±
The yellow engine diagnos-
tics warning lamp comes
on
while the engine is run-
ning. There may be a malfunction:
R
in the fuel injection system
R in the exhaust system
R in
the ignition system (on vehi-
cles with a petrol engine)
The emission limit values may be
exceeded and the engine may be
running in emergency mode. X
Have the vehicle checked as soon as possible at a qualified spe-
cialist workshop. H
The yellow tyre pressure
monitor* warning lamp is
on. G
Risk of accident
The tyre pressure monitor* has
detected a sudden or significant
pressure loss in at least one of
the tyres. X
Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do so.
X Observe the additional messages in the multi-function display
(Y page 219).
The warning light will go out after the flat tyre has been changed
and you have been driving for a few minutes. 1
The red SRS warning lamp
is lit while the engine is
running. G
Risk of injury
The restraint systems are faulty.
The airbags or belt tensioners
may either be triggered uninten-
tionally
or, in the event of an acci-
dent, not be triggered at all. X
Visit a qualified specialist workshop immediately. Practical advice
* optional
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Troubleshooting
251Warning tones
Problem Possible cause/consequence Suggested solutions
The anti-theft alarm system* is
suddenly triggered. You have opened the vehicle
using
the emergency key element
without deactivating the anti-
theft alarm system* first. X
Switch off the alarm (Y page 61). You hear a warning tone. A message appears in the multi-
function display. X
See the explanations for the display message ( Y page 219).You hear a warning tone. You are driving with the parking
brake applied. X
Release the parking brake. You hear a warning tone. You have opened the driver's
door and forgotten to switch off
the lights. X
Turn the light switch to M or U.You hear a warning tone.
G
Risk of injury
The driver or front passenger has
not fastened their seat belt. X
Fasten your seat belt ( Y page 88).You hear a continuous tone. You have switched off the engine
and opened the bonnet or the
driver's
door with Hold activated. X
Deactivate HOLD (Y page 145). Practical advice
* optional
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