2001 BMW 540I SEDAN check engine

Index
Data
Technology
Repairs
Car care
Controls
Overview
145nDisc brakes
Driving notes
When driving in wet conditions and in
heavy rain, it is effective to apply light
pressure to the brake pedal every few
miles (kilometers). Watch traffic condi-
tions to ensure that this maneuver does
not endanger other road users. The
heat which is generated by the brake
applications helps to dry the brake
pads and rotors.
Maximum braking force is obtained
while the wheels continue to rotate,
peaking when the wheels remain on the
verge of locking without actually doing
so. ABS maintains this state automati-
cally. If the ABS fails, you should revert
to the staggered braking technique
described below (refer to page 147).
Extended or steep mountain descents
should be driven in the gear in which
only minimal periodic brake applica-
tions is required. This avoids excessive
strain on the brakes and possible im-
pairment of the braking effect.
The braking effect of the engine can be
further increased by downshifting, into
first gear, if necessary. In the manual
mode of the automatic transmission,
you can also downshift into first gear.
Refer to page 76. Should engine braking prove inade-
quate, you should still avoid extended,
continuous braking. Instead of main-
taining low to moderate pressure over
an extended period of time, you should
decelerate by applying more substantial
pressure to the brake pedal (watch for
following traffic!), then releasing the
pedal, then repeating the application.
This staggered braking technique
allows the brakes to cool in the intervals
between active braking phases,
preventing overheating and ensuring
that full braking capacity remains avail-
able at all times.
Do not coast with the clutch de-
pressed or with the transmission
or selector lever in Neutral. Do not
coast with the engine shut off. The
engine provides no braking effect when
the clutch is depressed or the transmis-
sion is in neutral, and there is no
power-assist for braking or steering
when the engine is not running.
Never allow floor mats, carpets or any
other objects to protrude into the area
around the accelerator, clutch and
brake pedals and obstruct their move-
ment. <
Dynamic Brake Control (DBC)*
If you apply the brakes rapidly, this
system automatically produces the
maximum braking force boost and thus
helps to achieve the shortest possible
braking distance during "panic stops."
All of the benefits of the ABS system
are exploited under these circum-
stances.
Do not reduce the pressure on the
brake pedal for the duration of the
brake application. When the brake
pedal is released, the DBC is deacti-
vated.
In the event of a malfunction, the yellow
warning lamp comes on. Conventional
braking efficiency is available without
limitations.
Have the system checked and repaired
at your BMW center as soon as possi-
ble.
For "Information for your safety"
covering the ABS system, refer to
page 144. This information also gener-
ally applies for DBC. <

Index
Data
Technology
Repairs
Car care
Controls
Overview
165nEngine oil
Checking oil level
1 Park the vehicle on a level surface.
2 Shut the engine off after it has
reached normal operating
temperature.
3 After approx. 5 minutes, pull the dipstick out and wipe it off with a
clean lint-free cloth, paper towel, or
similar material.
4 Carefully push the dipstick all the way into the guide tube and pull it out
again.
5 The oil level should be in between the
two marks on the dipstick.
As with fuel economy, oil consumption
is directly influenced by your driving
style and vehicle operating conditions.
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The oil volume between the two marks
on the dipstick corresponds to approx.
1.1 US quarts (1 liter). Do not fill beyond
the upper mark on the dipstick. Excess
oil will damage the engine.
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To add oil
Wait until the level has dropped to just
above the lower mark before adding oil.
However, do not wait until the oil level
drops below the lower mark.
BMW engines are designed to op-
erate without oil additives; the use
of additives could lead to damage in
some cases. This is also true for the
manual transmission, the automatic
transmission, the differential, and the
power steering system. <
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Index
Data
Technology
Repairs
Car care
Controls
Overview
167nEngine oil Coolant
Comply with the applicable envi-
ronmental laws regulating the dis-
posal of used oil. <
Recommendation: have the oil changed
by your BMW center. Continuous exposure to used oil
has caused cancer in laboratory
testing. For this reason, any skin areas
that come into contact with oil should
be thoroughly washed with soap and
water.
Always store oil, grease, etc., out of
reach of children. Comply with all warn-
ing labels and information on lubricant
containers. < Do not add coolant to the cooling
system when the engine is hot. If
you attempt to do so, escaping coolant
can cause burns.
To avoid the possibility of damage later
on, never use anything other than fac-
tory-approved, nitrite and amino-free
extended-duty antifreeze with corrosion
inhibitor. Your authorized BMW center
is familiar with the official specifica-
tions.
Antifreeze and anticorrosion agents are
hazardous to health. You should always
store them in their original container
and in a location which is inaccessible
to children.
Extended-duty antifreeze with corro-
sion inhibitor contains the flammable
substance ethylene glycol. For this rea-
son, do not spill antifreeze with corro-
sion inhibitor on hot engine parts. It
could catch fire and cause serious
burns. <
Comply with the applicable envi-
ronmental laws regulating the dis-
posal of extended-duty antifreeze with
corrosion inhibitor. <
Checking coolant level
Correct coolant level when the engine
is cold (approx. 68 7/20 6):
Unscrew the cap from the expansion
tank.
The coolant level is correct when the
upper end of the red float is at least
even with the upper edge of the filler
neck (refer to the arrow in the illustra-
tion), but no more than 0.8 in (2 cm)
above it – that is, up to the second mark
on the float (refer also to the schematic
diagram next to the filler neck).
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168nCoolant Brake fluid
Adding coolant
Wait until the engine cools before
removing the cap from the expansion
tank. The needle of the coolant temper-
ature gauge in the instrument cluster
must be located in the blue zone; other-
wise, there is a danger of scalding.
1 Start by turning the cap counter-
clockwise. Pause to allow any
accumulated pressure to escape,
then open.
2 If the coolant is low, slowly add coolant until the correct level is
reached – do not overfill.
The coolant is a mixture of water and
extended-duty antifreeze with corrosion
inhibitor. Always maintain the pre-
scribed all-season 50:50 mixture ratio
for year-round protection against inter-
nal corrosion. No other additives are re-
quired.
Replace the coolant every four years.
If the indicator lamp for the
brake hydraulic system comes
on or if the "CHECK BRAKE
FLUID" warning appears in the
Check Control
*: the brake fluid
level is too low in the reservoir.
The brake fluid reservoir is located
under the microfilter housing on the
driver's side of the car. Should you de-
termine that the brake fluid is low, refer
the problem to your BMW center, who
can trace and rectify any sources of
leakage when refilling the reservoir.
Your BMW center is familiar with the
specifications for approved brake
fluids (DOT 4).
Brake fluid loss results in extended
pedal travel. For this situation, refer to
the notes on page 146.
Brake fluid is hygroscopic, that is,
it absorbs moisture from the air
over time.
In order to ensure the safety and
reliability of the brake system, have
the brake fluid changed every two years
by an BMW center. Refer also to the
Service and Warranty Information
Booklet (US models) or to the Warranty
and Service Guide Booklet (Canadian
models).
Brake fluid is toxic and damages the
vehicle's paint. You should always store
it in its original container and in a loca-
tion which is out of reach of children.
Do not spill the fluid and do not fill the
brake fluid reservoir beyond the "MAX"
mark. The brake fluid could ignite upon
contact with hot engine parts and
cause serious burns. <
Comply with the applicable
environmental laws regulating the
disposal of brake fluid. <

170n
The BMW Maintenance System has
been designed as a reliable means of
providing maximum driving and operat-
ing safety – and as cost-effectively as
possible for you.
Please keep in mind that regular main-
tenance is not only necessary for the
safety of your vehicle, but also plays a
significant role in maintaining the resale
value of the vehicle.
Service Interval Display
Advanced technology is employed to
calculate the optimal maintenance in-
tervals, which are then indicated in the
Service Interval Display. While conven-
tional systems rely on distance traveled
alone to determine when service is due,
the BMW Maintenance System has for
years considered the actual conditions
under which the vehicle operates, be-
390us702
cause mileage can be accumulated in
very different ways.
From a maintenance standpoint,
62,000 miles (100,000 km) accumulated
in short-distance urban driving are not
the equivalent of the same distance
covered at moderate speeds in long-
distance highway travel.
The BMW Maintenance System
includes the Engine Oil Service and
Inspections I and II.
Determining the maintenance intervals
according to the actual loads on the
vehicle covers every kind of operating
situation. However, even those who
drive only short distances – significantly
less than 6,000 miles (10,000 km) annu-
ally – should have the engine oil
changed at least every 2 years since oil
deteriorates over time, regardless of
use.Service and Warranty Information
Booklet (US models) or Warranty
and Service Guide Booklet (Cana-
dian models)
Please refer to the Service and War-
ranty Information Booklet (US models)
or to the Warranty and Service Guide
Booklet (Canadian models) for addi-
tional information on maintenance inter-
vals and procedures.
As a precaution against rust, it might be
a good idea to have the body checked
for damage from rocks or gravel at the
same time, depending upon operating
conditions. Have your BMW center do the
maintenance and repair.
Your BMW center is always informed on
the latest maintenance work and repair
techniques and equipped with the re-
quired special tools. In addition, check-
ing parts known from experience to be
subject to wear is a permanent part of
the maintenance specifications.
Be sure that all maintenance work is
confirmed in the Service and Warranty
Information Booklet (US models) or in
the Warranty and Service Guide Book-
let (Canadian models).
These entries will constitute your proof
that the vehicle has received regular
maintenance. They are also required in
the event of a warranty claim. <
The BMW Maintenance System

178nOBD interface socket
The Onboard Diagnostic (OBD) socket
is located on the left of the driver's side
at the bottom of the instrument panel
and under a cover (arrow).
The cover has the letters "OBD" on it.
The purpose of the OBD system is to
ensure proper emission control system
operation for the vehicle's lifetime by
monitoring emission-related compo-
nents and systems for deterioration and
malfunction.
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An illuminated 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.
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 se-
riously damage emission control com-
ponents, especially the catalytic con-
verter.
Service Engine Soon warning
lamp for Canadian models.When the filler cap is not properly
tightened, the OBD system can
detect the vapor leak and the indicator
will light up. If the filler cap is subse-
quently tightened, the indicator should
extinguish within a few days. <

Index
Data
Technology
Repairs
Car care
Controls
Overview
183nLamps and bulbs
The lamps and bulbs make essential
contributions to the safety of your vehi-
cle. For this reason, follow the instruc-
tions below carefully when replacing a
bulb. If you are not familiar with any of
the procedures, consult your BMW
center.
Do not touch the glass portion of a
new bulb with your bare hands
since even small amounts of impurities
burn into the surface and reduce the
service life of the bulb. Use a clean
cloth, paper napkin, or a similar mate-
rial, or hold the bulb by its metallic
base. <
A replacement bulb set is available from
your BMW center.
Whenever working on the electri-
cal system, switch off the electri-
cal accessory you are working on or
disconnect the cable from the negative
terminal of the battery. Failure to do this
could result in short circuits.
To prevent injuries and damage, com-
ply with any instructions provided by
the bulb manufacturer. <
The illustration shows the right-hand
engine compartment.
For checking and adjusting head-
lamp aim, please contact your
BMW center. <
1 Low beams
2 High beams
H7 bulb, 55 watts
The H7 bulb is pressurized. There-
fore, wear safety glasses and pro-
tective gloves. Failure to comply with
this precaution could lead to injury if the
bulb is accidentally damaged during re-
placement. <
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1 Turn the bulb holder to the left (arrow)
and remove.
2 Remove and replace the bulb.
When cleaning the headlamps,
please observe the following:
> Do not wipe dry (scratches). Never
use abrasives or strong
solvents to clean the covers.
Remove dirt and contamination (such
as insects) by soaking with BMW Car
Shampoo and then rinsing with plenty
of water.
Always use a deicer spray to remove
accumulated ice and snow – never
use a scraper. <

194nBattery
Never allow sparks or open
flame near the battery. Do not
smoke in the vicinity of the
battery. Avoid sparks from electrical
cables or electrical equipment. Turn the
key to position 0 in the steering lock
during the disconnection or connection
of the battery. Never short-circuit the
battery terminals. There is a danger of
injury from powerful sparks.
A highly-explosive gas is
generated when the battery is
charged.
If you happen to get acid in your
eyes, rinse thoroughly for
15 minutes with clear water.
Following that, consult a physician
immediately. If you get acid spray on
your skin or clothing, rinse with plenty
of water. If electrolyte is accidentally
swallowed, consult a physician immedi-
ately.
In order to protect the battery
case from ultraviolet radiation,
do not place it in direct sunlight.
A discharged battery can freeze. Store
the battery in areas where the tempera-
ture remains above freezing.
Charge condition
You can read the charge condition
of the battery with the "Magic Eye"
*
(a hydrometer):
> Green: adequate charge.
> Black: not charged adequately.
The battery must be recharged.
Please contact your BMW center.
> Yellow: replace the battery.
The projected service life of the
battery can only be reached if the
battery is fully-charged at all times.
Check the charge condition of the bat-
tery frequently if the vehicle is used pri-
marily for driving short distances. <
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Charging the battery
If the battery is charged in the vehicle:
Do not charge the battery with the
engine running.
Before performing any work on
the electrical system, disconnect
the cable from the negative terminal. If
you do not, short circuits can create the
risk of fire or personal injury. <
If you plan to store the vehicle for more
than four weeks, disconnect the battery
from the vehicle electrical system by
disconnecting the cable at the negative
terminal and then recharge using a suit-
able charging device.
If you intend to store your vehicle for
longer than 12 weeks: remove the bat-
tery, charge it and store it in a cool (but
frost and dust-free) room. Every three
months and before reinstalling the bat-
tery, have it recharged. If it is not
recharged, it will not be serviceable.
Every time the battery is discharged,
especially over extended periods, its
service life is reduced.