2005 MERCEDES-BENZ C CLASS COUPE check engine

341
Practical hints
What to do if …
Problem
Possible cause
Suggested solution
3
(Canada only)
;
(USA only)
The red brake warning lamp
comes on while driving and
you hear a warning sound.
You are driving with the
parking brake set.

Release the parking brake
(page 50).
The red brake warning lamp
comes on while driving.
There is insufficient brake fluid
in the reservoir.

Risk of accident! Carefully stop the
vehicle and notify an authorized
Mercedes-Benz Center. Do not add
brake fluid! This will not solve the
problem.
Warning!
G
Driving with the brake warning lamp illumi-
nated can result in an accident. Have your
brake system checked immediately if the
brake warning lamp stays on. Don’t 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.

342 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
ú
(USA only)
±
(Canada only)
The yellow engine
malfunction indicator
lamp comes on while
driving.
There is a malfunction in:

The fuel management system


The ignition system


The emission control system


Systems which affect emissions
Such malfunctions may result in ex-
cessive emissions values and may
switch the engine to its limp-home
(emergency operation) mode.

Have the vehicle checked as soon as possi-
ble by an authorized Mercedes-Benz Center.
An on-board diagnostic connector is used
by the service station to link the vehicle to
the shop diagnostics system. It allows the
accurate identification of system
malfunctions through the readout of
diagnostic trouble codes. It is located in the
front left area of the footwell next to the
parking brake pedal.
A loss of pressure has been detect-
ed in the fuel system. The fuel cap
may not be closed properly or the
fuel system may be leaky.

Check the fuel cap (
page 288).
If it is not closed properly:

Close the fuel cap.
If it is closed properly:

Have the fuel system checked by an
authorized Mercedes-Benz Center.
Your fuel tank is empty.

After refuelling start, turn off and restart the
engine three or four times in succession.
The limp-home mode is canceled. You do not
need to have your vehicle checked.

344 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
The yellow fuel tank reserve
warning lamp in the fuel gauge
comes on while driving.
The fuel level has gone below the reserve
mark.

Refuel at the next gas station
(page 288).
<
The red seat belt telltale illumi-
nates for a brief period after
starting the engine.
The telltale reminds you and your passengers
to fasten seat belts.

Fasten your seat belt.
The telltale goes out.
The red seat belt telltale
illuminates and a warning chime
sounds for approximately six
seconds after starting the
engine.
The driver’s seat belt is not fastened before
the engine is started.

Fasten the driver’s seat belt.
The telltale goes out.
1
The red SRS indicator lamp
comes on while driving.
There is a malfunction in the restraint
systems. The air bags or emergency
tensioning devices (ETDs) could deploy
unexpectedly or fail to deploy in an accident.

Drive with added caution to the
nearest authorized Mercedes-Benz
Center.
Warning!
G
In the event a malfunction of the SRS is
indicated as outlined above, the SRS may
not be operational.
For your safety, we strongly recommend
that you visit an authorized Mercedes-Benz
Center immediately to have the system
checked; otherwise the SRS may not be
activated when needed in an accident,
which could result in serious or fatal injury,
or it might deploy unexpectedly and unnec-
essarily which could result in an accident
and/or injury to you or to others.

357
Practical hints
What to do if …
Symbol messagesDisplay symbol
Display message
Possible cause
Possible solution
#
Battery Alternator
Visit workshop.
The battery is no longer charging:

broken poly-V-belt


alternator malfunctioning

Stop immediately 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. Notify
an authorized Mercedes-Benz Center.
If it is intact:

Drive immediately to the nearest
authorized Mercedes-Benz Center.
Low voltage
Charge battery
The battery has insufficient voltage.

Start the engine (
page 48).
Low voltage
Switch off consumers
The battery has insufficient voltage.

Turn off unnecessary electrical
consumers

358 Practical hintsWhat to do if …Display symbol
Display message
Possible cause
Possible solution
!
(Canada only)
;
(USA only)
Parking brake
Release brake.
You are driving with the parking brake
set.

Release the parking brake
(page 50).
2
Brake wear
Visit workshop.
The brake pads have reached their wear
limit.

Have the brake pads replaced as soon
as possible.
;
(USA only)
3
(Canada only)
Brake fluid
Visit workshop.
There is insufficient brake fluid in the
reservoir.

Risk of accident! Stop the vehicle and
notify an authorized Mercedes-Benz
Center. Do not add brake fluid! This
will not solve the problem.
Warning!
G
Driving with this message 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.

359
Practical hints
What to do if …
Display symbol
Display message
Possible cause
Possible solution
B
Coolant
Check level
The coolant level is too low.

Add coolant (
page 296).

If you have to add coolant frequently,
have the cooling system checked by
an authorized 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 can be seriously burned.
!Do not ignore the low engine coolant
level warning. Extended driving with
the 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.

361
Practical hints
What to do if …
Display symbol
Display message
Possible cause
Possible solution
•
Coolant
Stop, engine off!
The poly-V-belt could be broken.

Stop immediately 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. Notify an
authorized Mercedes-Benz Center.
If it is intact:

Do not continue to drive the vehicle with
this message displayed. Doing so could
result in serious engine damage that is
not covered by the Mercedes-Benz
Limited Warranty.

Observe the coolant temperature gauge
(page 24).

Drive immediately to the nearest
authorized Mercedes-Benz Center.
Coolant
Visit workshop.
The cooling fan for the coolant is
malfunctioning.

Observe the coolant temperature gauge.

Have the fan replaced as soon as
possible.

363
Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
:
USA only:At next gas station
add 1.0 qt engine oilCanada only:At next gas station
add 1.0 l engine oil
The engine oil level is too low.

Add engine oil (
page 294) and check
the engine oil level (
page 293).
Engine oil level
Stop, engine off!
There is no oil in the engine. There is a
danger of engine damage.

Carefully bring the vehicle to a halt as
soon as possible.

Turn off the engine.

Add engine oil (
page 294) and check
the engine oil level (
page 293).
Engine oil level
Reduce oil level
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.
Change engine oil
Visit workshop.
It may be that there is water in the engine
oil.

Have the engine oil checked.