2004 BMW 525I SEDAN check engine light

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Indicator and warning
lamps
Technology that monitors itself
The indicator and warning lamps identified
by the
+ symbol are subjected to an oper-
ation check each time you switch on the
ignition or start the engine. They each light
up once for different periods of time.
When a malfunction occurs in a monitored
system, the corresponding lamp will either
fail to go out when the engine is started, or
it will come on again during normal driving.
For information on how you should respond
when this happens, please refer to the
pages indicated.
Colors
The indicator and warning lamps can light
up in different colors and combinations.
The following section explains the signifi-
cance of the individual colors as well as
how you should respond when they
appear.
>Red:
Stop immediately
or
important reminder
>Red and yellow:
Continue driving moderately
>Yellow:
Have checked soon
or
for your information
>Green or blue:
For your information.
Indicator and warning lamps of the
Check Control
Other indicator and warning lamps appear
in display 6 of the instrument cluster as
necessary, accompanied by supplemen-
tary text on the Control Display, refer to
Check Control, page 68. Turn signal indicators 56
Active steering
+82
Handbrake/brake fluid, brake
hydraulics/DBC Dynamic Brake
Control
+50/ 180/ 79
Handbrake/brake fluid, brake
hydraulics/DBC Dynamic Brake
Control for Canadian models
Airbags
+83
Service Engine Soon
+183
If the indicator lamp comes on
either continuously or intermit-
tently, this indicates a fault in the
emissions-related electronic sys-
tems. Although the vehicle
remains operational, you should
have the systems checked by your
BMW center at the earliest possi-
ble opportunity.
Service Engine Soon indicator
lamp for Canadian models.
Front fog lamps 89
ABS Antilock Brake System
+77
DTC Dynamic Traction Control79
High beams/headlamp flasher 88
Please fasten safety belt
+40
DSC Dynamic Stability
Control
+78
Check Gas Cap168
lamp for US models

Technology for comfort, convenience and safety
78
CBC Cornering Brake Control
CBC is a supplement to ABS. It provides
further enhancements in vehicle stability
and steering response during lane changes
and cornering at high rates of lateral accel-
eration.
EBV Electronic Brake Force
Distribution
EBV controls the brake system's applica-
tion pressure at the rear wheels to ensure
stable deceleration.
In case of malfunction
If the brake system warning lamp
lights up in red, appearing together
with the yellow indicator lamps for
ABS and DSC:
The driving stability control has
failed.
If all three lamps light up yellow:
Fault in the driving stability control.
The EBV electronic brake-force distribution
is active.
While you may continue, you should
remember to proceed cautiously and drive
defensively while avoiding full brake appli-
cations.
Please have the system checked at the
nearest BMW center.
If a message appears on the Control Dis-
play, please note the supplementary infor-
mation.
You can find more information on the
Check Control starting on page 68.
Indicator and warning lamps for
Canadian models.
Driving stability control/
DSC Dynamic Stability
Control
The concept
DSC maintains vehicle stability, even in
critical driving situations.
The DSC is operational every time you start
the engine. DSC includes the functionality
of the DTC Dynamic Traction Control and
DBC Dynamic Brake Control, refer to
page 79.
The system optimizes vehicle stability dur-
ing acceleration and when starting from a
full stop, as well as optimizing traction. The
system recognizes any tendency for the
vehicle to assume an unstable attitude
such as oversteer or understeer; it then
counteracts this tendency with a combina-
tion of graduated reductions in engine
torque and selective braking intervention at
individual wheels. DSC provides optimal
stability within the limits defined by the
laws of physics.
Indicator lamps
The indicator lamp in the instrument
cluster goes out soon after you start
the engine.
If the indicator lamp flashes:
DSC is regulating the drive and braking
forces.
If the indicator lamp lights up permanently:
DSC has been switched off using the but-
ton.
If the indicator lamp and the brake
warning lamp light up permanently:
Malfunction in DSC, DTC and DBC.
When the system is off, the stability main-
tenance functions described above are no
longer available. The vehicle will remain
completely operational, however, without
DSC.
Please respond to any malfunctions by
referring the problem to your BMW center.

Technology for comfort, convenience and safety
80 tance during panic stops. This system
exploits all of the benefits provided by ABS.
Do not reduce the pressure on the brake
pedal for the duration of the brake applica-
tion. When the brake pedal is released,
DBC is deactivated.
In the event of a malfunction, the
warning lamp in the instrument
cluster lights up yellow.
Have the system checked and repaired at
your BMW center as soon as possible.
Please note any information that appears
on the Control Display.
Warning lamp for Canadian models.
Active roll stabilization*
The concept
Active roll stabilization minimizes body roll
and optimizes vehicle stability during cor-
nering and evasive maneuvers.
Dynamic stabilizers at the front and rear
axles form the basis for active roll stabiliza-
tion. Suspension compliance adapts to suit
driving conditions, varying from perfor-
mance-oriented during cornering to
smooth and comfort-oriented when the
vehicle is proceeding in a straight line.
The system assumes operational status
each time you start the engine.
Driving with active roll stabilization
During vehicle operation, the system con-
tinuously runs through closed-loop control
cycles lasting only fractions of a second.
In case of malfunction
The symbol in the instrument clus-
ter lights up and a message
appears on the Control Display.
Please note any supplementary information
that appears there.
You can find more information on the
Check Control starting on page 68. If the active roll stabilization system is
deactivated in response to malfunc-
tion, please remember to adapt your speed
accordingly, especially in curves.
The suspension will be noticeably softer
and the vehicle will display a greater ten-
dency to tilt during cornering and in cross-
winds.
If a message stating that you should stop
appears on the Control Display in addition
to the red symbol, stop immediately and
switch off the engine. In this case the oil
level in the reservoir may have dropped
below the minimum, possibly owing to a
leak in the hydraulic system.
Please note any supplementary information
that appears on the Control Display.<
Flat Tire Monitor
The concept
The Flat Tire Monitor keeps track of the
inflation pressures in the four fitted tires as
you drive. The system provides an alert
whenever the inflation pressure drops sig-
nificantly in relation to the pressure in
another tire.
The check of the tire inflation pressure is
based on monitoring the relative speeds of
the wheels. A flat tire is detected and
reported on the basis of a deviation in cer-
tain speed ratios.
Functional requirement
So that the Flat Tire Monitor can learn the
correct inflation pressure, please perform
the following:
1.Check the inflation pressures in all tires
2.Compare with the inflation pressure
table on page 170 and correct if neces-
sary
3.Initialize the system.
Limits of the system
The Flat Tire Monitor cannot indicate
sudden severe tire damage caused
by outside factors and does not detect a

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natural, even pressure drop in all four
tires.<
In the following situations, on the other
hand, there can be delays in detecting tire
pressure losses, and even system failure:
>When you are driving on snow-covered
or slippery road surfaces
>If you are using a sports driving style:
slip on the drive wheels, high lateral
acceleration
>False alarms and undetected loss of
pressure may occur when you are driv-
ing with snow chains fitted
>When you are driving with the compact
wheel, the Flat Tire Monitor is unable to
function.
Initializing the system
Perform the initialization immediately
after correcting the inflation pressure,
after changing a tire or changing a wheel or
all wheels. A drive is necessary for this pur-
pose.<
Control Center, for principle details, refer to
page 16:
1.Before beginning driving, start the
engine, but do not drive off
2.Open the menu
3.Select "Vehicle settings" and press the
controller
4.Select "FTM" and press the controller
5.Select "Set tire pressure" and press the
controller
6.Select "Yes" and press the controller
7.Drive off.
The message "Initializing" is displayed.It takes a few minutes before the Flat Tire
Monitor can detect and report a flat tire.
After the initialization is completed, the
message "Active" is displayed.
If a flat tire is detected during initialization,
a message appears on the Control Display.
When driving with snow chains or
with the compact wheel, do not initial-
ize the system.<
Flat tire
Indicator lamp
The symbol in the instrument clus-
ter lights up in red and a simulta-
neous message appears on the
Control Display. In addition, an acoustic
signal sounds.
Please note any supplementary information
that appears on the Control Display. You
can find more information on the Check
Control starting on page 68.
1.Reduce speed and stop the vehicle
carefully. Avoid sudden braking and
steering maneuvers
2.Identify damaged tire
If identification is not possible,
contact your BMW center.<
3.Replace the damaged wheel, refer to
Changing a tire on page 187.
Vehicles with run-flat tires:
1.Cautiously reduce the vehicle speed to
below 50 mph/80 km/h. Avoid sudden
braking and steering maneuvers. Do
not exceed a vehicle speed of 50 mph/
80 km/h
Due to the reinforcement on the
edges of the run-flat tires, inflation
pressure loss can not usually be recog-
nized from the outside, refer to Run-flat
tires on page 175.<
2.To continue driving, comply with the
instructions for driving with damaged
tires on page 175.

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The risk of hydroplaning increases as the
tread depth of the tires decreases, refer
also to Tire tread on page 173.
Water on the road
Do not drive through water on the
road if it is deeper than 1 ft/30 cm,
and then only at walking speed at the most.
Otherwise, the vehicle's engine, the electri-
cal systems and the transmission may be
damaged.<
Brakes
Your BMW is equipped with ABS as stan-
dard. The best way to achieve optimized
response from the ABS is to apply maxi-
mum pressure to the brake pedal during
emergency: panic stops. Since the vehicle
maintains steering responsiveness, you
can nevertheless avoid possible obstacles
with a minimum of steering effort.
Pulsation at the brake pedal combines with
sounds from the hydraulic circuits to indi-
cate to the driver that ABS is in its active
mode.
Do not drive with your foot resting on
the brake pedal. Even light but con-
sistent pedal pressure can lead to high
temperatures, brake wear and possibly
even brake failure.<
Driving in wet conditions
While driving in wet conditions and in
heavy rain, it is a good idea to apply light
pressure to the brake pedal every few
miles. Monitor traffic conditions to ensure
that this maneuver does not endanger
other road users. The heat generated in this
process helps dry the pads and rotors to
ensure that full braking efficiency will then
be available when you need it.
Hills
You can retain full and unimpaired braking
efficiency by downshifting to a gear in
which only minimal brake applications are
needed when descending long or steep
downhill stretches. You can further enhance the engine's brak-
ing effect by selecting a lower gear in the
automatic transmission's manual mode,
downshifting as far as first gear on
extremely steep stretches, refer to
pages 50 and 55. This strategy helps you
avoid placing excessive loads on the brake
system.
Never drive with the clutch pressed or
allow the vehicle to coast with the
transmission in Neutral Ð or with the engine
switched off Ð there is no engine braking
when the transmission is in Neutral, and no
power-assist for brakes and steering when
the engine is not running.
Never allow floor mats, carpets or any other
objects to protrude into the area around the
accelerator and brake pedals and obstruct
their movement.<
Corrosion on the brake rotors
When the vehicle is driven only occasion-
ally, during extended periods when the
vehicle is not used at all, and in operating
conditions where brake applications are
less frequent, there is an increased ten-
dency for corrosion to form on rotors, while
contaminants accumulate on the brake
pads. This occurs because the minimum
pressure which must be exerted by the
pads during brake applications to clean the
rotors is not reached.
Should corrosion form on the brake rotors,
the brakes will tend to respond with a pul-
sating effect that even extended applica-
tion will fail to cure.
Brake pads
The brake pad wear warning lamp
lights up and a message appears on
the Check Control. Please note any
supplementary information that appears
there.
Warning lamp for Canadian models.
The brake pads have reached their mini-
mum pad thickness. Have them replaced at
your BMW center as soon as possible.

Under the hood
180
Checking coolant level
Correct coolant level with the engine cold,
approx. +687/206:
1.Turn the cap of the expansion tank
counterclockwise to allow any accumu-
lated pressure to escape, then continue
turning to open
2.The coolant level is correct when the
coolant extends to between the MIN
and MAX marks on the filler neck, refer
to the diagram adjacent to the filler
neck
3.If the coolant is low, slowly add coolant
up to the specified level Ð do not overfill.
Brake fluid
The symbol lights up and a mes-
sage appears on the Control Dis-
play: the brake-fluid level in the
container is too low.
The brake fluid reservoir is located under
the microfilter housing trim panel on the
driver's side of the vehicle. To have brake
fluid added to the system, or to have the
source of any brake fluid loss traced and
rectified, please contact your BMW center,
which can also supply the factory-
approved Ð DOT 4 Ð brake fluids.
Brake fluid is hygroscopic: it absorbs
moisture from the atmosphere over
the course of time.
To ensure that the brake system continues
to provide safe and reliable performance,
remember to have the brake fluid changed
every 2 years at the latest, refer to page 66
and to the Service and Warranty Informa-
tion Booklet for US models or the Warranty and Service Guide Booklet for Canadian
models.
Brake fluid is toxic and also damages vehi-
cle paintwork. Always store these agents in
tightly-closed original containers kept well
away from the reach of children.
Do not spill the fluid and do not refill the
brake fluid reservoir to beyond the MAX
mark. Should it come into contact with hot
engine components, the brake fluid could
ignite and cause personal injury in the form
of burns.<
Always observe all applicable rules
and regulations for environmental
protection when disposing of used brake
fluid.<
Warning lamp for Canadian models.
Brake hydraulic systems
A low brake-fluid level combined with
longer-than-usual pedal travel could be a
sign that one of the brake system's hydrau-
lic circuits has failed.
Proceed to the nearest BMW center.
Remember that pedal travel may be
increased, and there may also be a sub-
stantial increase in the amount of pedal
pressure required to brake the vehicle.
Please adapt your driving style accord-
ingly.<

Mobility
183Reference
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Rules and regulations
California Proposition 65
Warning
California laws require us to issue the fol-
lowing warning:
Engine exhaust and a wide variety of
automobile components and parts,
including components found in the interior
furnishings in a vehicle, contain or emit
chemicals known to the State of California
to cause cancer and birth defects and
reproductive harm. In addition, certain flu-
ids contained in vehicles and certain prod-
ucts of component wear contain or emit
chemicals known to the State of California
to cause cancer and birth defects or other
reproductive harm.
Battery posts, terminals and related acces-
sories contain lead and lead compounds.
Wash your hands after handling.
Used engine oil contains chemicals that
have caused cancer in laboratory animals.
Always protect your skin by washing
thoroughly with soap and water.<
OBD connector
The Onboard Diagnostic OBD interface
socket is located on the left of the driver's
side under the instrument panel and under
a cover.
The cover has the letters OBD on it.
The purpose of the OBD system is to
ensure proper operation of the emission
control system for the vehicle's lifetime.The system monitors emissions-related
components and systems for deterioration
and malfunction.
An illuminated indicator lamp
informs you of the need for service,
not of the need to stop the vehicle.
However, the systems should be checked
by your BMW center at the earliest possible
opportunity.
Indicator lamp for Canadian mod-
els.
Under certain conditions, the indicator will
blink or flash. This indicates a rather severe
level of engine misfire. When this occurs,
you should reduce speed and consult the
nearest BMW center as soon as possible.
Severe engine misfire over only a short
period of time can seriously damage emis-
sions control components, especially the
catalytic converter.
When the fuel filler cap is not properly
tightened, the OBD system can
detect the vapor leak and the indicator
lamp will light up. If the filler cap is subse-
quently tightened, the indicator lamp
should go out within a few days.<

Everything from A to Z
204 Cargo, securing 109
Cargo area
Ð locking separately 31
Caring for artificial leather,
refer to Caring for your
vehicle brochure
Caring for leather, refer to
Caring for your vehicle
brochure
Caring for light-alloy
wheels, refer to Caring for
your vehicle brochure
Caring for plastic, refer to
Caring for your vehicle
brochure
Caring for the carpet, refer
to Caring for your vehicle
brochure
Caring for the vehicle finish,
refer to Caring for your
vehicle brochure
Car jack
Ð jacking points 188
Car keys, refer to Central
keys with remote
control 26
Car phone 151
Ð installation location, refer
to Center armrest 98
Ð refer to Portable
phone 150
Ð refer to separate Owner's
Manual
Car radio, refer to
Radio 134
Car wash 106
Ð refer also to Caring for
your vehicle brochure
Catalytic converter, refer to
High temperatures 106
"Categories" 138
CBC Cornering Brake
Control 78
CBS Condition Based
Service 181
"CD" 130CD changer 144
Ð adjusting the tone 131
Ð controls 130
Ð fast forward/reverse 146
Ð installation location 144
Ð listening to a CD 144
Ð playing a track 145
Ð random order 146
Ð repeating a track 145
Ð selecting track 145
Ð switching on/off 130
Ð volume 131
CD for navigation 114
CD player 141
Ð adjusting the tone 131
Ð controls 130
Ð fast forward/reverse 142
Ð playing a track 142
Ð random order 142
Ð repeating a track 142
Ð selecting tracks 141
Ð switching on/off 130
Ð volume 131
Center armrest 98
Center console, refer to
Comfort area 14
Central keys with remote
control 26
"Central locking" 38
Central locking system 27
Ð from inside vehicle 30
Ð from outside vehicle 27
Changes, technical, refer to
Parts and accessories 6
Changing a wheel 187
Changing selector-lever
positions 55
Changing the direction
display for navigation 124
Changing the language on
the Control Display 74
Changing the
measurement units on the
Control Display 74
Changing wheels 174
CHECK button 69
Check Control 68
"Check Control
messages" 69
Check Gas Cap 168Checking the air pressure,
refer to Tire inflation
pressure 170
Child's seat 45
Child-restraint fixing
LATCH 47
Child restraints 45
Child-restraint system 45
Child-safety lock 48
Chock 187
Chrome parts, care, refer to
Caring for your vehicle
brochure
Cigarette lighter 100
Circulation of air, refer to
Recirculated-air mode 91
"City" for destination
entry 117
Cleaning, refer to Caring for
your vehicle brochure
Cleaning headlamps
Ð washer fluid 57
Cleaning windshield 57
"Climate" 41
Clock 65
Ð 12/24 hour mode 74
Ð setting the time and
date 74
Closing
Ð from inside 30
Ð from outside 27
Cockpit 10
Comfort area 14
Comfort seat 37
"Communication" 152
"Communication
interface" 161
Compact Disc
Ð refer to CD changer 144
Ð refer to CD player 141
Compact wheel
Ð inflation pressure 171
Ð wheel change 187
Compression ratio, refer to
Engine data 198
Computer 70
Ð clock, 12/24 hour
mode 74
Ð displays on the Control
Display 70