1997 BMW 525i Activate

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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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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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1 Brakes
- Remove precharge pump mounting bracket fasteners and re-
move pump.
- Installation is reverse of removal, noting the following:
Be sure to replace rubber pump mounts if damaged
01
worn.
Bleed brakes as described earlier.
Tightening torque Brake line
to precharge pump 18 Nrn (13 ft-lb)
DSC pressure sensor (1 999 - 2002 models)
On 1999 and later DSC systems, the DSC pressure sensor is
screwed into the DSC hydraulic unit (right rear of engine com-
partment).
WARNING-
* €39 cars require special BMW service equipment to prop-
erly bleed the brakes. Removal of the
DSCpressure sensor
is not recommended unless this equipment is available. For
safety reasons, the brake system on cars with ABS must be
bled using the procedures described in this repair group.
Switch off ignition and remove
key to male sure brake
system cannot be activated.
- Disconnect electrical harness connector at switch.
- Use BMW special tool 34 5 160 to remove and install sensor.
Inspect threads and sealing surfaces for damage.
* Work quicltly to avoid excessive brake fluid leakage.
Tightening torque
Pressure sensor
to hydraulic 19 Nrn (14ft-lb)
unit
- Reconnect harness connector
- Bleed front brakes as described earlier.
- Press on brakes and check for leaks at sensor.
- Turn on ignition and firmly depress brake pedal. Check that
DSC warning light does not come on.

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51 2-2
I Door Windows 1
This repair group covers door glass, window regulator and
power window motor repair information.
CA U JIO&
All E39 models are equipped with side-impact airbags in the
front doors. Some models are also equipped with
airbags in
the rear doors. Be sure to read the
airbag warnings and cau-
tions in 721
Airbag System (SRS).
Electric window switch replacement is covered in 612
Switches.
The windshield, rear window, fixed rear doorglass, and cargo
compartment glass (Sport Wagon only) are bonded using
special adhesives and tools. It is recommended that bonded
glass replacement be done by an authorized
BMW service fa-
cility or an automotive glass installer.
Special tools
Some window repair operations require special tools.
Power windows
- Power window features in E39 models include:
Control of the front and rear door window motors is carried
out directly by the General Module (GM
Ill).
One-touch operation in both directions on all four windows.
Cable type window regulator used for all door windows.
. Anti-trap protection provided by pressure sensitive finger
guard.
Right front and each rear door has a single window switch
located in door handle trim.
Rear door window switches can be deactivated by press-
ing child lock-out switch in the driver's window switch block.
Convenience closinglopening of the windows from driver's
loci( cylinder or convenience opening only from remote un-
lociting feature (FZV) remote key.
Window (FZV) operation can be owner customized with
Car Memory function. See 515 Central Locking and Anti-
Theft.
After ignition is switched off, electric windows can be oper-
ated until a door is opened or until
I6 minutes has elapsed.
The GM
IiI bases window motor end position on current
draw (load). There is a maximum window motor run time of
6 seconds. The motor is then switched off even if the end
position load sensor fails.

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51 2-3
Door Windows
Window switches
4 The push type window switch provides the GM Ill with a cod-
ed ground signal. Holding a switch at the first detent provides
a single ground signal on one wire requesting the GM
Ill to
open the window. When released, the ground signal is re-
moved and the window motor stops.
- Momentarily pushing the switch to the second detent and re-
leasing provides an additional ground signal on the second
wire requesting "one touch mode". The GM
Ill lowers the win-
dow automatically until it reaches the end position. Each win-
dow has four positions, two each for the standard mode of
operation and two for the one-touch mode. All window oper-
ation signals are digital inputs to the door modules and GM
111.
- The switch functions in the same manner for window closing
but the ground signal sequence is reversed.
4 Window switch positions.
1. Off
2. Open
3. One touch open
4. Close
5. One touch close
Rear window child lockout switch
4 The rear window child lockout switch (arrow) is incorporated
in the driver's window switch block in
leit front door arm rest.
When activated, it provides a constant ground signal to the
GM
Ill, preventing the windows from being operated from the
rear door switches.
- The lockout switch ground signal is overridden by the GM Ill
if a passive safety system (MRS) crash signal is received.

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51 2-4
I Door Windows
/ Anti-trap strip
Power window motors
The window motors are mounted on cable regulators. The
window motor control circuit consists of two wires for operat-
ing the motor in both directions.
The motors are activated by relays in the GM
Ill. The relays
provide either power or ground depending on the direction of
window travel. The GM
Ill controls the polarity based on a re-
quest to run the window from a window switch or a conve-
nience
openinglclosing signal.
Convenience openinglclosing
The GM Iii provides the convenience openlclose feature, pro-
viding control of the power windows (and sunroof) from out-
side the vehicle with the key in the driver's door lock. The FZV
(remote key) provides the same function for window opening
only.
Anti-trap protection is active during convenience closing from
the driver's door lock.
If the GM receives a request to operate convenience closing
or opening for more than
110 seconds, the function is deacti-
vated and a
fault code is stored.
Window anti-trap protection
4 A rubber pressure guard is located at the top edge of each
door frame. It consists of two contact strips that close when
subjected to pressure. When the contact strip closes (for ex-
ample, a hand is trapped between the top of the window and
the door frame), an anti-trap signal is sent to the GM
Ill. The
window immediately (within
10 milliseconds) reverses direc-
tion. This feature does not require
initialization.
The E39 pressure sensor finger guard has a resistance of 3
Kw and it is monitored for open circuits. When pressed, the
monitored resistance changes to
< 1 Kw. if anti-trap protection
becomes faulty the one touch window closing will not func-
tion.
Window anti-trap protection is
only active in the one touch
and convenience close modes of operation. If the window
switch is pulled and held, anti-trap protection will not function.
The anti-trap contact strip has a resistance of
1.2 K Ohm and
it is monitored for open circuits. Faults with the anti-trap sys-
tem will cancel the one touch feature requiring the window
switch be held to close the window.

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Door windows1
Window motor limit stop function
If repeated window activation (upldown cycles) exceeds one
minute, the
GM Ill deactivates the internal relays and disre-
gards any further
upldown requests. The GM Ill provides mo-
tor activation after a short duration but not for the full one
minute monitoring cycle.
The
GM Ill monitors the number of times a window motor is
activated. It counts each cycle and stores the number in
memory. Afler the stop function limit is reached and the win-
dow motor is deactivated, the
GM Ill slowly reverses the
stored count of activation until the stored number equals
0,
thus allowing the window motor to cool down.
WARNING-
* Always wear hand and eye protection when working with
brolen glass.
If a window is brolen, all of the glass bits should be
vacuumed out of the door cavity. Use a blunt
so-ewdi-iv-
er to clean out any remaining glass pieces from the
window guide rails.
When servicing the door windows, the harness con-
nector to the window regulator should always be dis-
connected to prevent pinching fingers in the moving
window mechanism.
Sedan and Sport Wagon doors are similar. Use the following
procedures for window service on these models.
WARNING-
E39 cars are iitted with side-impact airbags in the front
doors. Some are equipped with
airbags in the rear doors
as well. When
servicing the door windows on cars with
side-impact airbags, always disconnect the negative
(-)
battery cable. See 721 Airbag System (SRS) for cau-
tions and procedures relating to the
airbag system.
* Prior to disconnecting the battery, read the battery dis-
connection cautionsgiven
001 General Warnings and
Cautions.

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Central Locking and Anti-Theft
DWA alarm
The DWA alarm system is
armedldisarmed when thevehicle
is locked / unlocked from either the door or trunk.
Convenience closing
I opening
The windows and sun roof can be closed or opened by hold-
ing the key in the
loclc I unlock position.
Crash sensor
The crash sensor is located in the left front
kick panel. It func-
tions by unlocking all doors in the event of an accident.
NOTE-
Continuous and repeated locliing / unlocking may cause
timedarrest of
the locliing system. When activated, the timed
arrest lasts for two minutes. The timed arrest does not affect
the crash sensor
unlocliing the doors in case of an accident.
Door locks
The driver's door lock location is the only point outside of the
vehicle where the ltey can mechanically control all of the cen-
tral locking system functions.
4 Door key positions for electrical / manual loclting and
unlocking are:
1. Manual unlock
2. Unlock, DWA disarmed, convenience open
(hold until activated)
3. Neutral position
4. Lock, DWA armed, convenience closing
(hold until activated)
5. Manual lock
The door lock actuators are sealed. self contained units with
no replaceable parts. The
actuators use Hall effect sensors in
place of pin contacts and microswitches to provide DOOR
OPEN
I DOOR CLOSED status signal. Each door lock button
only affects the actuator it controls. There is no effect on the
other doors.
An automatic locking feature activates door locks when a
road speed signal of 4 mph is detected via the K-Bus. The fac-
tory default coding for this feature is OFF, but can be coded
ON for individual users with the Key Memoryfunction. See
Car Memory
1 Key Memory later in this section.