1998 BMW 528i engine control system

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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.
-

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320-8
Steering and Wheel Alignment
4 MFL steering wheel: Loosen 2 airbag mounting fasteners
(Torx T27 or T30) located at rear of steering wheel (arrow).
4 Sport steering wheel:
Insert screwdriver through opening in rear of steering
wheel and push against spring tension to release
airbag.
Repeat procedure on other side of steering wheel.
- Carefully lift airbag from steering wheel and disconnect elec-
trical harnesses from
back side of unit. Refer to component
illustrations above. Also see
721 Airbag System (SRS).
Improper handling of the airbag could cause serious injury.
Store the
airbag with the horn pad facing up. If stored facing
down, accidental deployment couldpropel it violently into the
Avoid damaging the variety of convenience switches, such
as radio and cruise controls, installed in the steering wheel of
4 Remove steering wheel center bolt (arrow).

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--
C. -- -- - -- Rear ~us~ensionl
Depending on year and model applications, the Sport Wagon
rear suspension may be equipped with:
Conventional shock absorbers and coil springs
Electronic height control (EHC) system which incorporates
air springs
NOTE-
. Suspension and EHC troubleshooting is covered in 300
Suspension, Steering and Brakes-General.
EHC system repairs, other than air spring replacement,
are covered in Electronic height control
(EHC) compo-
nent replacement.
Replace shock absorbers and springs in pairs only.
Rear shock absorber, removing and
installing
- Raise car and remove rear wheels,
WARNING-
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 parts.
CAUTION-
If working on a vehicle with compressedairshock absorbers,
disable air supply pump by disconnecting electrical plug be-
fore performing any repairs. Pump is located beneath a cover
under the spare tire in the floor of the cargo compartment.
- Support swing arm from below
CAUTIOG
The shock absorber prevents the drive axle and wlieel bear-
ing carrier from dropping too far. Supporting the wheel bear-
ing carrier before disconnecting the shock absorber
mounting fasteners prevents damage to the
brake hose,
parking
brake cable and drive axle CVjoints.
- Working in cargo compartment, remove carpet. Remove tri-
angular upper shock mount covers located beside spare tire
well.
- If applicable: Detach air supply line from shock absorber.
Plug ports and lines to keep out dirt.

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Rear Suspension
Air spring, removing and installing
CAUTION-
If vehicle is driven with airspring depressurized, the airspring
will be permanently damaged and must be replaced.
An air spring is made from a flexible rubber material which
forms an airtight cavity. It is pressurized by an air supply
pump activated by an electronic control unit to provide a
vari- . . able spring rate depending on vehicle load
CAUTIOIG
Disable air supply pump by disconnecting electrical plug
before performing any repairs. Pump is located beneath a
cover under the spare tire in the floor of
the cargo compart-
ment.
When removing and installing air connections, extreme
cleanliness must be followed. Small dirt particles can
cause leakage in the system.
Remove luggage compartment floor mat.
- Working above air spring, loosen quick coupling screw con-
nection to allow
air pressure to escape.
- Once pressure has been reduced, retighten screw.
Tightening torque Quick coupling screw
to air pump 2 Nm (18 in-lb)
- Remove quick coupler. Plug openings to keep dirt out,
- Remove air spring mounting clips.
- Raise car and remove rear wheels.
Make sure the car is firmly supported on jack stands de-
signed for the purpose. Place jack stands underneath struc-
tural chassis points. Do not place
jaclc stands under
suspension parts.
- Working underneath rear suspension, lift wheel bearing car-
rier to relieve rear spring tension. Then unbolt air spring
mounting bolt from seat on wheel bearing carrier. Remove air
spring.
NOTE-
Left and right air springs are different. The left air spring is
marked with a red identification
marl. The right air spring is
marked with a blue identification mark.

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330-26
/ Rear Suspension
Remove inner control arm eccentric nut and bolt (A)
Remove control arm ball joint nut (6). Press ball joint out
of wheel bearing carrier.
Lifl out control arm.
Installation is reverse of removal, noting the following:
Use previously made
marks to install eccentric bolt and
nut.
Always use new self-locking nuts.
Tighten fasteners to final torque only after vehicle has
been lowered and suspension has settled.
0 Have car professionally aligned when job is complete.
Tightening
torques
Road wheel to hub 120klONm
(89 i7 ft-lb)
Upper front control arm (traction strut) to 60
Nm (44
ft-lb)
subframe (rear toe adjusting bolt)
Upper front control arm (traction strut) to wheel
65 Nm (48 ft-lb)
carrier
Rear axle assembly, removing and
installing (sedan models)
In case of damage to the subframe, or if a pressed-in bushing
is worn, remove
subframe by removing complete axle assem-
bly.
- Raise car and remove rear wheels.
WARNING-
Make sure 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 parts.
- Remove exhaust system. See 180 Exhaust System
- Detach driveshaft from differential. See 260 Driveshaft.
- Remove brake caliper and brake disc. Hang brake caliper
aside with stiff wire. Do not disconnect brake fluid hose. See
340 Brakes.
- Remove lefl and right ABS sensors from wheel bearing car-
riers.
- Disconnect parking brake cable from brake shoe expander.
See 340 Brakes.
- Remove heat shield from above driveshaft.

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330-35
Rear Suspension
- Remainder of installation is reverse of removal, noting the fol-
lowing.
Always use new self-loclting nuts.
Make sure all threaded bolts, nuts and mating suriaces are
clean.
Make sure long lower strut bushing fits in hole in wheel
bearing carrier.
Tighten fasteners to final torque only after vehicle has
been lowered and suspension has settled.
Stake axle collar nut after tightening.
Tightening torques
ABS pulse sensor to wheel bearing carrier
8 Nm (6 ft-lb)
Brake rotor to hub 16 Nm (12 ft-lb)
Rear brake pad carrier (caliper) to wheel 65
Nm (48
ft-lb)
bearing carrier
Rear axle shaft to hub
(M27) 300 Nm (221 ft-lb)
Rear strut to wheel bearing carrier 127
Nrn (94 ft-lb)
Road wheel to hub
120+10 Nm
(89
i7 ft-lb)
Swing arm to wheel bearing carrier 256
Nrn (189 ft-lb)
Upper front control arm (traction strut) to 65 Nrn
(48
ft-lb)
wheel carrier
Upper rear control arm to wheel carrier 142
Nrn (105
ft-lb)
Rear wheel bearing carrier, removing and
installing (Sport Wagon models)
- Raise rear end of car and remove wheel.
WARNING-
Make sure 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 parts.
Models
with air springs: Disable air supply pump by discon-
necting electricalplug
beforepedormingany repairs. Pump is
located beneath a cover under the spare tire in the floor of the
cargo compartment.
-- 4 Models with air springs: Loosen compressed air pipes (ar-
rows) at air distribution assembly to release system pres-

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---
Rear Suspension
ELECTRONIC HEIGHT CONTROL
(EHC) COMPONENT REPLACEMENT
Sport Premium rear suspension is an option on Sport Wagon
models and standard on
1999 and later V-8 Sport Wagons.
This suspension incorporates electronic height control
(EHC)
using air springs.
With vehicle lifted off the ground,
if the rear air springs can be
compressed by hand, either the spring is defective or the sys-
tem is depressurized.
Locate
EHC faults using BMW scan tools DIS or MoDiC. EHC
description and some troubleshooting is covered in 300 Sus-
pension, Steering and Brakes-General.
Air spring replacement is covered earlier in this chapter. See
Air spring, removing and installing.
CAUTION-
Maintain high levels of cleanliness around air line connec-
tions when disassembling and assembling air suspension
components. Even
small dirt particles can cause leakage in
the pressurized system.
Electronic height control
(EHC) components
1. Air spring
2. 1 liter air reservoir
3. EHC control module
4. Air supply distributor
5. Airsupply pump
(under spare tire)
6. Air spring mounting bolt
(at wheel bearing carrier)
7. Rear ride height sensors
(Hall effect)
8. Air supply pump relay

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-- I
I: ... . -. Rear Suspension! -- .- -
Air compressor pump relay, removing and
installing
- Working in cargo compartment, remove spare wheel.
4 Remove air supply pump fasteners (arrows). Turn pump
over.
- Turn relay plug 45" and remove relay.
EHC control module, removing and
installing
The EHC control module is mounted on the right side of the
spare tire
well in the cargo compartment.
- Remove spare tire.
4 Remove electrical components cover (A).
- Release control module wiring harness plug loclting clip (B)
and remove module.
- Installation is reverse of removal.
- After assembly, reset ride height using BMW diagnostic scan
tool DIS.
Air supply unit, removing and installing
CAUTION-
Maintain high levels of cleanliness around air line connec-
tions when disassembling and assembling air suspension
components. Even small dirt particles can cause
leakage in
the pressurized system.
When the airsupply unit is removed for any reason, reset ride
height using BMW scan tools DIS or
MoDiC.
- Remove spare tire.
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