2008 MERCEDES-BENZ B-CLASS HATCHBACK check engine light

Display
messages 219Display messages Possible cause/consequence Possible solution
. Parking lamp front
left
or
Parking lamp front
right Vehicles with the lights and visibility pack-
age*: the front left-hand or front right-
hand parking lamp is faulty. X
Change the bulb (Y page 244). . Reversing lamp
left
or
Reversing lamp
right Vehicles with lights and visibility pack-
age*: the left-hand or right-hand reversing
light is faulty. X
Visit a qualified specialist workshop. . Tail lamp left
or
Tail lamp right Vehicles with lights and visibility pack-
age*: the left-hand or right-hand tail lamp
is faulty. X
Change the bulb (Y page 244). N Add 1.0 litreof
engine oil when
next refuelling Vehicles with a diesel engine: the oil level
is too low. X
Check the oil level (Y page 172).
X If necessary, top up the motor oil.
X Have the engine checked for leaks if the engine
oil needs topping up more often than usual. N Engine oil pres-
sure Stop car, turn
eng. off Vehicles with a petrol engine: the engine
oil pressure is too low. There is a risk of
engine damage. X
Stop in accordance with traffic conditions.
X Switch off the engine.
X Check the oil level (Y page 172).
X If necessary, top up the motor oil. Practical advi
ce
* optional
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Display
messages 220 Display messages Possible cause/consequence Possible solution
N Eng. oil level
Check level Vehicles with a petrol engine: the oil level
is too low. X
Check the oil level (Y page 172).
X If necessary, top up the motor oil.
X Have the engine checked for leaks if the engine
oil needs topping up more often than usual. N Eng. oil level Stop
car, turn eng. off Vehicles with a diesel engine: the oil level
is too low. There is a risk of engine dam-
age. X
Stop in accordance with traffic conditions.
X Switch off the engine.
X Top up the engine oil and check the level
(Y page 172). N Engine oil level
Reduce oil level Vehicles with a diesel engine: you have
added too much engine oil. There is a risk
of damage to the engine or to the catalytic
converter. X
Siphon off excess engine oil until it is at the
specified level. Observe the legal require-
ments. N Cannot measure oil
level Vehicles with a diesel engine: the meas-
uring system is faulty. X
Visit a qualified specialist workshop. I Key does not belong
to vehicle You have put the wrong key in the ignition
lock. X
Use the correct key. I Remove key The key is in the ignition lock. X
Remove the key. I Replace key The key needs to be replaced. X
Visit a qualified specialist workshop. Ñ SPEEDTRONIC inop-
erative
Speedtronic* and cruise control* are
faulty. X
Visit a qualified specialist workshop. Practical advi
ce
* optional
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Troubleshooting
227Problem Possible cause/consequence Suggested solutions
H
The red brake system
warning lamp comes on
while the engine is run-
ning. G
Risk of accident
There is insufficient brake fluid in
the fluid reservoir. X
Pull over and stop the vehicle safely, paying attention to road and
traffic conditions. Do not continue driving under any circumstan-
ces.
X Consult a qualified specialist workshop immediately.
X Observe the additional messages in the multi-function display
(Y page 202).
Do not top up the brake fluid. This will not rectify the fault. ±
The yellow engine diagnos-
tics warning lamp lights up
while the engine is run-
ning. Vehicles with a diesel engine: the
fuel tank has been run dry. X
Start the engine three to four times after refuelling.
Emergency running mode is cancelled. The vehicle need not be
checked. ±
The yellow engine diagnos-
tics warning lamp lights up
while the engine is run-
ning. There may be a fault, for example
R
in the engine management
R in the ignition system
R in the exhaust system
R in the ignition system (for vehi-
cles with petrol engines)
The emission limit values may be
exceeded and the engine can run
in emergency mode. X
Have the vehicle checked as soon as possible at a qualified spe-
cialist workshop. Practical advice
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Troubleshooting
234 Problem Possible cause/consequence Suggested solutions
Vehicles with a petrol engine:
The engine is not running
smoothly and is misfiring. There is a malfunction in the
engine electronics or a mechani-
cal component of the engine con-
trol unit. X
Only depress the accelerator pedal slightly.
X Have the cause rectified immediately at a qualified specialist work-
shop.
Otherwise, non-combusted fuel may get into the catalytic converter
and damage it. A coolant temperature of over
120 °C is displayed. The coolant
warning lamp may also be on and
a warning tone may sound
(Y
page 97). The coolant level is too low. The
coolant is too hot and the engine
is no longer being cooled suffi-
ciently. X
Stop as soon as possible and allow the engine and the coolant to
cool down.
X Check the coolant level (Y page 175). Observe the warning notes
as you do so and top up the coolant if necessary. If the coolant level is correct, the
radiator fan may be faulty. The
coolant is too hot and the engine
is no longer being cooled suffi-
ciently. X
If the coolant temperature is less than 120 °C, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving on
mountain roads and stop/start driving. Practical advice
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Troubleshooting
235AUTOTRONIC*
Problem Possible cause/consequence Suggested solutions
The transmission has problems
shifting gear The transmission is losing oil. X
Have the transmission checked at a qualified specialist workshop
immediately. The acceleration ability is deteri-
orating.
The one-touch gearshifting is no
longer working.
The transmission no longer
changes gear. The transmission is in emergency
mode. X
Stop the vehicle.
X Move the selector lever to position P.
X Turn the key to position 0in the ignition lock.
X Wait at least 10 seconds before restarting the engine.
X Move the selector lever to position Dor R.
X Have the transmission checked at a qualified specialist workshop
immediately. Practical advice
* optional
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Troubleshooting
239Key
Problem Possible cause/consequence Suggested solutions
You cannot lock or unlock the
vehicle using the key. The key batteries are discharged
or nearly discharged. X
Point the tip of the key at the driver's door handle from close range
and try to unlock or lock the vehicle again.
If this does not work:
X Unlock the vehicle using the emergency key element
(Y page 241).
X Check the key batteries (Y page 244) and replace them if neces-
sary (Y page 244). The key is faulty. X
Unlock the vehicle using the emergency key element
(Y page 241).
X Have the key checked at a qualified specialist workshop. The battery charge indicator lamp
of the key does not go on during
the test. The key batteries are discharged. X
Change the batteries (Y page 244).You have lost a key. X
Have the key cancelled at a Mercedes-Benz Service Centre.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the manual locks changed too. You have lost the emergency key
element. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the manual locks changed too. The engine cannot be started
using the key. The steering lock is mechanically
blocked. X
Remove the key and reinsert it into the ignition lock. While doing
this, turn the steering wheel in both directions. Practical advice
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Changing bulbs
246
Rear bulbs Bulb Type
7
Third brake
lamp LED
8
Turn signal lamp PY 21 W
9
Reversing lamp P 21 W
a
Licence plate
lamp C 5 W
b
Rear foglamp P 21 W
c
Tail lamp P 5 W
d
Brake lamp P 21 W
Before changing bulbs
You can replace the following bulbs:
R
Dipped-beam headlamps (halogen head-
lamps)
R Main-beam headlamps (halogen head-
lamps)
R Side lamp/parking lamp
R Cornering light* (vehicles with bi-xenon
headlamps *)
R Front turn signal lamp R
Brake lamp
R Tail lamp
R Turn signal lamp (rear)
R Licence plate lamp
Observe the following points:
R Use only the bulb types specified here.
R To prevent a short-circuit, switch off the
lights before changing a bulb.
R Only hold bulbs with a clean, lint-free cloth.
R Do not work with wet or greasy fingers.
R If the new bulb still does not light up, con-
sult a qualified specialist workshop, e.g. a
Mercedes-Benz Service Centre.
i Due to the location of the bulbs in the
front headlamps, it is best to have these
changed at a qualified specialist workshop,
e.g. a Mercedes-Benz Service Centre.
i Have the headlamp setting checked reg-
ularly at a qualified specialist workshop,
e.g. a Mercedes-Benz Service Centre. Changing the front bulbs
Removing/fitting the washer fluid res-
ervoir You must remove the washer fluid reservoir
from the engine compartment before you can
replace the bulbs in the front left-hand head-
lamp.
X
To remove: turn retaining screw 1anti-
clockwise.
X Remove washer fluid reservoir 2from
bracket 3.
X Put washer fluid reservoir 2to one side
and leave the lines and hoses connected.
Make sure that no washer fluid escapes.
X To fit: guide the lower retaining lug into the
rubber grommet on the longitudinal mem- Practical advice
* optional
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Towing and tow-starting
2671
Positive terminal of donor battery
2 Positive terminal on your vehicle
3 Negative terminal of donor battery
4 Negative terminal on your vehicle
X Open the battery cover ( Ypage 264).
X Connect positive terminal 2on your vehi-
cle to positive terminal 1of the donor bat-
tery using the jump lead, beginning with
your own battery.
X Start the engine of the donor vehicle and
run it at idling speed.
X Connect negative terminal 3of the donor
battery to negative terminal 4of your
vehicle's battery using the jump lead, con-
necting the jump lead to the donor battery
first.
X Start the engine. X
Electrical consumers can be switched on
again. Do not, however, switch on the lights
as this places too heavy a load on the bat-
tery.
X Remove the jump lead from earth
point 4and negative terminal 3first,
then from positive terminals 1and 2,
each time disconnecting from the battery
on your own vehicle first.
X Have the battery checked at a qualified
specialist workshop, e.g. a Mercedes-Benz
Service Centre. Towing and tow-starting
Points to remember
G
Risk of accident
If you have the vehicle towed, you must use
a rigid towing bar if:
R the engine is not running.
R there is a brake system malfunction.
R there is a malfunction in the voltage sup-
ply or the vehicle's electrical system.
The electric power steering and the brake
force booster do not work when the engine
is not running. Greater braking force will
then be required and brake pedal travel will
be longer. If necessary, depress the brake
pedal with full force.
Do not tow the vehicle if the key cannot be
turned in the ignition lock. If this is the case,
the steering is locked and the vehicle can-
not be steered.
If you tow or tow-start another vehicle, its
weight must not exceed the maximum per-
missible gross vehicle weight of your vehi-
cle.
It is better to have the vehicle transported
than to have it towed. Practical advice
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