2000 BMW 528i air con

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300-1 4
I Susoension. Steerina and Brakes - General
DSC system I
Dynamic Stability Control (DSC)
Dynamic Stability Control (DSC) utilizes many principles and
components of the ASC traction control system. DSC is ac-
tive throughoutthe driving range, unlike ASC which is only ac-
tive during acceleration and braking. DSC helps stabilize the
vehicle in cornering and avoidance maneuvers by adjusting
engine controls such as throttle, ignition, fuel injection and the
application of
brake pressure individually to the wheels.
Inputs
fi- 0
2 4-* .. o
[11-' IJ
411m4
3?-
G
4 The DSC control module uses various inputs to determine
vehicle instability during braking, cornering, or reduced trac-
tion situations. Based upon these inputs the ABSIDSC con-
trol module sends outputs to the engine control module and
the ABSIDSC hydraulic unit to activate torque reduction pro-
tocols and braking intervention.
-
ABSIDSC control module
OUI~YIS
4
The DSC system can be toggled on and off by a switch
mounted on the center console. Turning off the DSC system
does not disable ABS or ASC functions.
+
Measure ride height (A) from center of fender arch to bottom
of wheel rim.
Car in normal loaded position on the ground. See Normal
loaded position.
Engine
control
module
Specified tires and wheels, correct tire pressure, even tire
wear
-'* 9-
.%A
Correct wheel bearing play
T'== ..t, 9 B
-.m
Model with air suspension (EHC): Disconnect electrical har-
ness connector to air supply pump to prevent automatic
height regulation.
When finished, reset ride height using BMW diagnostic
scan tools DIS or
MoDiC.
NOTE-
Airsupply pump is located beneath a cover under the spare
tire in the floor of the cargo compartment.
- If ride height is outside specification listed, install new
springs. Suspension spring removal and installation is cov-
ered in
310 Front Suspension and 330 Rear Suspension.
Normal loaded position
Each front seat 68 kg (150 Ib)
Center of rear seat 68 kg (150 lb)
Trunk 21 kg (46 lb)
Fuel tank full

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300-1 6
I Suspension, Steering and Brakes - General
Rear
ride height specifications
(measurement
A)
E39 6-cylinder (5251,5281,530i) models
E39 VB (540i) models
Wheel size
15 inch
16 inch
17 inch
18 inch
Maximum variation between sides: 10
mm (.04 in)
Maximum deviation from specifications: 10
mm (.04 in)
Standard
suspension
547 mm (21.5 in)
560
mm (22.0 in)
575 mm (22.6 in)
588 mm (23.1 in)
I I I I I
Maximum variation between sides: 10 mm (.04 in)
Wheel
size
15 inch
16 inch
575 mm (22.6 in)
Maximum deviation from specifications: 10 mm
(.04 in)
Sports suspension
532 mm (20.9 in)
545 mm (21.5 in)
560 mm (22.0 in)
573
mm (22.6 in)
Rough road
suspension
567
mm (22.3 in)
580 mm
( in)
E39 Sport Wagon models
M sports package
536
mm (21.1 in)
549 mm (21.6 in)
Standard
suspension
547 mm (21.5 in)
560 mm (22.0 in)
588 mm (23.1
in)l 573 mm (22.6 in)/ 603 mm (23.7 in)l 608 mm (23.9 in)l 577 mm (22.7 in)
560
mm (22.0
in) Ride level
control
562
mm (22.1 in)
575 mm (22.6 in)
590 mm (23.2 in)
603 mm (23.7 in)
Sports suspension 532
mm (20.9 in)
545 mm (21.5 in)
590
mm (23.2 in) Rough
road
suspension
567
mm (22.3 in)
580 mm (22.8 in)
595 mm (23.4 in)
608 mm (23.9 in)
Ride level control
562
mm (22.1 in)
575 mm (22.6 in)
Wheel size
15 inch
M sports package
532
mm (20.9 in)
545
mm (21.5 in)
560 mm (22.0 in)
573 mm (22.6 in)
595
mm (23.4 in)
Sports suspension with
air spring
548 mm (21.5 in)
Standard
suspension
548
mm (21.5 in)
16 inch
17 inch
18 inch 564
mm (22.2
in)
Maximum variation between sides: 10 mm
(.04 in)
Maximum deviation from specifications: 10 mm
(.04 in) 561
mm (22.0 in)
576
mm (22.6 in)
589
mrn (23.1 in)
561
mm (22.0 in)
576 mm (22.6 in)
589 mm (23.1 in) Ride level
control
563
mm (22.1 in) Rough road suspension
568 mm (22.4 in)
576 mm (21.6 in)
591 mm (23.2 in)
604 mm (23.7 in) 581
mm (22.9
in)
596
mm (23.5 in)
609 mm (24.0 in)

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31 0-2
I Front Suspension
This repair group covers the repair and replacement of com-
ponents that make up the front suspension of E39 cars.
Two different types of steering systems are used in the E39
series. 6-cylinder
(5251,5281 and 530i) models are equipped
with a rack and pinion type steering system mounted to an
aluminum subframe.
V-8 (540i) models use a steering gear-
box type system mounted to a steel subframe.
See
300 Suspension, Steering and Brakes-General for a
description of the front suspension and components, as well
as specifications for setting ride height.
CAUTION-
Some E39 models are equipped with aluminum suspen-
sion components. The foiiowing cautions apply:
Due to the chemical and corrosion characteristics of
aluminum, do not bring into contact with battery acid.
* Do not clean with wire brushes with brass or iron bris-
ties. Only use brushes with stainless steei bristles.
Do not expose to flying sparks from grinding/cutting op-
erations.
* Do not subject to steei welding splashes.
Do not expose to temperatures over 80°C (176°F).
even for short periods. Temperatures in painting faciii-
ties are not a problem.
Special tools
Special service tools are required for most of the work de-
scribed in this repair group. In addition to the tools depicted in
the illustrations, avariety of press tools are necessaryfor con-
trol arm bushing replacement. Read the procedures through
before beginning any job.
31 2 210 I < Strut nut socket
(Tool No. 31 2 210)

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31 0-4
I Front Suspension
6-cylinder models
12 3 4 5
V-8 models
16 7 4
Front suspension
variations
1. Steering knuckle
2. Tension strut (thrust arm)
3. Steering rack
4. Front suspension
subframe
5. Outer tie rod
6. Control arm
7. Steering box
8. Idler arm
9. Center tie rod
The front suspension
shoclc absorbers on E39 cars are
MacPherson struts. The strut is a major component of the
front suspension and supports the spring. Most strut assem-
bly components are available as replacement parts. Always
replace struts and springs in pairs.
Front strut, upper strut mount or spring replacement is a two-
step procedure:
Removal of strut assembly from vehicle
Disassembly and replacement of component on
work
bench

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/~ront Susaension
Front suspension arms FRONT SUSPENSION ARMS
Scyllnder models (5251,5281,530i)
Control arms and tension struts are attached to the front sub-
Front suspension arms V-8 models (5401)
frame through rubber bushings and to the steering ltnuckles
by ball joints.
NOTE-
Tension struts are sometimes called thrust arms or thrust
rods.
Control arms or tension struts are sometimes called lower
front arms or lower rear arms.
Inspect ball joints for wear and looseness. lnspect bushings
for wear or fluid
lealts. The ball joint can only be replaced as
part of an entire suspension arm assembly. Some suspen-
sion arm
bushinas are available as re~lacement Darts. Al-
ways replace in pairs
NOTE-
Steering wheel vibration during braking (usually at road
speeds of
50 to 60 m.p.h.) are often causedby faulty suspen-
sion arm bushings, not out-of-true brake rotors.
Some special tools may be required to remove suspension
arms and to replace bushings. Read procedures through be-
fore beginning the job.
Control arm, removing and installing
(6-cylinder models)
- Raise car and remove wheel
Male sure
that the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural chassis points. Do not place jack stands under
suspension
parfs.
Cars equipped with vertical headlight adjustment system:
Disconnect control arm from level sensor.
Remove control arm fasteners (arrows). Lightly tap inner
control arm mounting bolt out of subframe.

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I Steerina and Wheel Alianment
Steering
system
Two types of steering gear are used in the E39 series models.
6-cylinder
(5251, 528i and 530i) models are equipped with
rack and pinion steering. The steering rack is mounted to
an aluminum subframe.
V-8
(540i) models are equipped with a recirculating ball
and nut steering gearbox mounted to a steel subframe.
At low speeds, maximum power assist is provided to ease
parking and city driving. At high speeds, assist is reduced to
ensure stability. The power steering system varies assist
based on engine speed.
Power boost for the steering is provided by an engine-driven
hydraulic pump. A hydraulic control valve is used to control
boost pressure.
The steering wheel connects to the steering gear via an ad-
justable steering column which incorporates a rubber cou-
pling ("guibo") to dampen vibration and noise.
Power steering fluid is supplied from the fluid
reservoir to the
pump and to the steering gear via rubberlmetal hoses.
The return line from the steering gear to the
reservoir loops
into the airstream in front of the radiator and connects to the
steering fluid cooler. The fluid cooler is attached to a cassette
which also includes cooling coils for engine oil, transmission
fluid and AIC condenser.
The steering gear requires no maintenance other than align-
ment and periodic inspection for worn components. Inspect
rubber rack boots
(rack and pinion system) and tie-rod end
boots periodically for tears or damage. Replace
if necessary.
-
NOTE-
The airbag system is traditionally referred to as Supplemen-
tal Restraint System (SRS). The
BMW versfon of SRS used
m the E39 models is known as the Multiple Restraint System - (MRS). - -

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Steering and Wheel Alignment
Steering system warnings and cautions
WARNING -
The BMW airbag system is complex. Special precautions
must be observed when servicing the system. Serious in-
jury may result if system service is attempted by persons
unfamiliar with the BMW
airbag system and its approved
service procedures. BMW specifies that all inspection and
service should be
peiformed by an authorized BMW deal-
e,:
The BMW E39 is equipped with an airbag mounted in
the steering wheel. The
airbag is an explosive device
and should be treated with extreme caution. Always fol-
low the
airbag removal procedure as outlined in 721
Airbag System (SRS).
BMW airbags are equipped with a bacli-up power sup-
ply inside the
airbag control module. A 5 second wait-
ing period should be observed after the battery cable
has been disconnected. This will allow the reserve
power supply to discharge.
Do not reuse self-locking nuts. They are designed to
be used only once and may fail if reused. Always re-
place them with new locliing nuts.
* Do not install bolts and nuts coated with undercoating
wax, as correct tightening torque cannot be assured.
Always clean the threads with solvent before installa-
tion, or install new parts.
Do not attempt to weld or straighten any steering com-
ponents. Always replace damagedparts.
CAUTION--
- Some E39 models are equipped with aluminum suspen.
sion components. The following cautions apply:
Due to the chemical and corrosion characteristics of
aluminum, do not bring into contact with battery acid.
Do not clean with wire brushes with brass or iron bris-
tles. Only use brushes with stainless steel bristles.
Do
not expose to flying sparks from grindinghutting op-
erations.
Do not subject to steel welding splashes.
* Do not expose to temperatures over 80% (176°F).
even for short periods. Temperatures in painting iacili-
ties are not a problem.

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320-7
Steering and Wheel ~liqnmentl
STEERING WHEEL
Steering wheel, removal and installation
WARNING -
The BMWairbag system (Supplemental Restraint System or
SRS) is complex. Special precautions must be observed
when servicing. Serious injury may result if
SRS system serv-
ice is
attempted by persons unfamiliar with the BMW SRS
and its approved service procedures. BMW specifies that all
inspection andservice should be preformed by an authorized
BMW dealer.
E39 cars may come with either one of two different styles of
steering wheel:
Multifunction (MFL) steering wheel
* Sport steering wheel
4 Multifunction (MFL) steering wheel components:
1. Cruise control 1 radio 1 telephone electrical harness
2. Horn button electrical harness
3. Airbag electrical harness
4. Radio / telephone control switch set
5. Air bag
6. Cruise control switch set
Sport steering wheel
3
5 0021413
4 Sport steering wheel components:
1. Switch carrier
2 Steering wheel switch set electrical harness
3. Airbag
4. Lower cover
5. Horn button and airbag electrical harness
- Center steering wheel. Make sure front wheels are pointed
straight ahead.
- Disconnect negative (-) cable from battery.
CA UTIOP&
Prior to disconnecting the battern read the battew discon-
nection cautions given in
001 General Cautions and
Warnings.
-