Practical Hints MERCEDES-BENZ SLK280 2007 R171 Owner's Guide

364 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
With the seat unoccupied and the ignition switched on,

the 75indicator lamp on the center console
should illuminate and remain illuminated, indicating that the OCS has
deactivated the passenger front air bag and the passenger-side knee
bag.

the message Front passenger airbag enabled See Operator’s
Manual
or the message Front passenger airbag disabled See
Operator’s Manual
should not appear in the multifunction display at
any time the seat is unoccupied. Wait at least 60 seconds for the sys-
tem to complete the necessary check cycles and to make sure neither
message appears in the multifunction display.
If above conditions are met, you can occupy the passenger seat again.
Depending on the passenger classification sensed by the
OCS (
page 71), the 75indicator lamp will remain
illuminated or go out.
If above conditions are not met, the system is not working properly. Have
the system checked as soon as possible by an authorized Mercedes-Benz
Center.
Warning!G
If the 75indicator lamp
remains illuminated with an adult occupant
on the passenger seat even after performing
the above corrective steps, do not have any passenger use the passenger seat until the
system has been repaired.

365 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
Run Flat
IndicatorinoperativeThe Run Flat Indicator* is malfunc-
tioning.Have the Run Flat Indicator* checked by an
authorized Mercedes-Benz Center.
The Run Flat Indicator* has been
switched off due to a malfunction.
Tire pressureCheck tiresThe Run Flat Indicator* indicates
that the pressure is too low in one or
more tires.Carefully bring the vehicle to a halt, avoiding
abrupt steering and braking maneuvers. Observe
the traffic situation around you.
Check and adjust the tire inflation pressure as
required (
page 314).
If necessary, change the wheel (page 401).
Restart the Run Flat Indicator* after adjusting the
tire inflation pressure values (
page 314).
Check tiresThen restart
Run Flat IndicatorThere was a warning message about
a loss in tire inflation pressure and
the Run Flat Indicator* has not been
restarted yet.Make sure that the correct tire inflation pressure
is set for each tire.
Then restart the Run Flat Indicator*
(
page 316).
Warning!G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle.
You may lose control of the vehicle. Contin-
ued driving with a flat tire will cause exces-
sive heat build-up and possibly a fire.

366 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
#The battery is no longer charging.
Possible causes:

Alternator malfunctioning

Broken poly-V-belt
Do not forget that the brake system
requires electrical energy and may
be operating with restricted capa-
bility. Considerably greater brake
pedal force is required and the stop-
ping distance is increased.
Stop the vehicle immediately in a safe loca-
tion and check the poly-V-belt.
If it is broken:
Do not continue to drive.
Otherwise, the engine will overheat due
to an inoperative water pump which may
result in damage to the engine. Contact
an authorized Mercedes-Benz Center.
If it is in order:
Contact an Mercedes-Benz Center
immediately. Adjust driving to be consis-
tent with reduced braking responsive-
ness.
USA only:
;
Canada only:
!
Release
parking brakeYou are driving with the parking
brake set.Release the parking brake (page 53).

367 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
USA only:
;
Canada only:
3
Check
brake fluid levelThere is insufficient brake fluid in
the reservoir.Risk of accident!
Stop the vehicle in a safe location or as soon as
it is safe to do so.
Turn off the engine.
Apply the parking brake (page 59).
Do not drive any further.
Contact an authorized Mercedes-Benz Center.
Do not add brake fluid! This will not solve the
problem.
2Brake wearThe brake pads have reached their
wear limit.Have the brake pads replaced as soon as
possible.
Warning!G
Driving with the message Check brake
fluid level
displayed can result in an
accident. Have your brake system checked
immediately. Do not add brake fluid before
checking the brake system.
Overfilling the brake fluid reservoir can
result in spilling brake fluid on hot engine
parts and the brake fluid catching fire. You
can be seriously burned.!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks.
!Brake pad thickness must be visually
checked by a qualified technician at the intervals
specified in the Maintenance Booklet.

368 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
•Coolant
Stop, turn engine
offThe coolant is too hot.
Among other possible causes,
the poly-V-belt could be broken.Stop the vehicle in a safe location or as soon as it is
safe to do so.
Turn off the engine.
Apply the parking brake (page 59).
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise, the engine will
overheat due to an inoperative water pump which
may result in damage to the engine. Contact an
authorized Mercedes-Benz Center.
If it is intact:
Wait for the message to disappear before restarting
the engine.
Doing otherwise could result in serious engine
damage that is not covered by the Mercedes-Benz
Limited Warranty.
(Continued on next page)

369 Practical hints
What to do if …
During severe operating conditions, e.g.
stop-and-go traffic, the coolant tempera-
ture may rise close to 248°F (120°C).
Display symbolDisplay messagePossible cause/consequencePossible solution
Observe the coolant temperature display
(
page 127).
If the temperature rises again:
Contact an authorized Mercedes-Benz
Center immediately.
Warning!G
Driving when your engine is overheated can
cause some fluids which may have leaked
into the engine compartment to catch fire.
You could be seriously burned.
Steam from an overheated engine can cause
serious burns and can occur just by opening
the hood. Stay away from the engine if you
see or hear steam coming from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.
!The engine should not be operated with the
coolant temperature above 248°F (120°C).
Doing so may cause serious engine damage
which is not covered by the Mercedes-Benz
Limited Warranty.

370 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
•The cooling fan for the coolant is
malfunctioning.Observe the coolant temperature display
(
page 127).
If the coolant temperature is below 120°C,
you may continue driving to the nearest
specialist workshop.
Avoid heavy loads on the engine (e.g. by
driving uphill) as well as stop-and-go traffic.
Have the fan replaced as soon as possible.
/Top up coolant
See Oper. ManualThe coolant level is too low.Add coolant (page 300).
Comply with all warnings while doing so.
If you have to add coolant frequently,
have the cooling system checked by an au-
thorized Mercedes-Benz Center.
Warning!G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You could be seriously burned.
!Do not ignore the low engine coolant level
warning. Extended driving with this message and
symbol displayed may cause serious engine
damage not covered by the Mercedes-Benz
Limited Warranty. Do not drive without sufficient
amount of coolant in the cooling system. The
engine will overheat, causing major engine
damage.

371 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
±Display malfunction
Drive to workshopCertain electronic systems are un-
able to relay information to the con-
trol system. The following systems
may have failed:

Coolant temperature display

Tachometer

Cruise control display
Have the electronic systems checked by an
authorized Mercedes-Benz Center.
JYou are driving with one or more
doors open.Close the doors.

372 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
NCheck oil level
when next refuelingSLK 280 and SLK 350 only:
The engine oil level has dropped to
a critical level.Check the engine oil level (page 296) and
add engine oil as required (
page 299).
If you must add engine oil frequently, have
the engine checked for possible leaks.
USA only:
Add 1 qt. engine oil
when next refueling
Canada only:
Add 1 liter engine oil
when next refueling
SLK 55 AMG only:
The engine oil level is too low.Add engine oil (page 299) and check the
engine oil level (
page 296).
Cannot measure
motor oil levelSLK 55 AMG only:
The measuring system is malfunc-
tioning.Have the measuring system checked by an
authorized Mercedes-Benz Center.

373 Practical hints
What to do if …
When the message Add 1 qt. (Canada:
1 liter) engine oil when next
refueling
(SLK 55 AMG) or Check oil
level when next refueling
(SLK 280,
SLK 350) appears while the engine is run-
ning and at operating temperature, the en-
gine oil level has dropped to approximately
the minimum level.
When this occurs, the warning will first
come on intermittently and then stay on if
the oil level drops further.Visually check for oil leaks. If no obvious oil
leaks are noted, drive to the nearest
service station where the engine oil should
be topped to the required level with an
approved engine oil. For information on
approved engine oils, refer to the Factory
Approved Service Products pamphlet
(USA only) or contact an authorized
Mercedes-Benz Center.
Display symbolDisplay messagePossible cause/consequencePossible solution
NEngine oil level
Reduce oil levelSLK 55 AMG only:
You have added too much engine
oil. There is a risk of damaging the
engine or the catalytic converter.Have oil siphoned or drained off.
Observe all legal requirements with respect
to its disposal.
Engine oil level
Stop, turn engine offThere is no oil in the engine. There
is a danger of engine damage.Stop the vehicle in a safe location or as soon
as it is safe to do so.
Turn off the engine.
Apply the parking brake (page 59).
Add engine oil (page 299) and check the
engine oil level (
page 296).
!The engine oil level warnings should not be
ignored. Extended driving with the symbol
displayed could result in serious engine damage
that is not covered by the Mercedes-Benz
Limited Warranty.