1998 BMW 525i ECO mode

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Central Body Electronics ZKE III
Objectives of the Module
After completing this module, you will be able to:
• List the functions directly controlled by the GM III.
• Describe how the GM III recognizes the key position from the drivers door.
• Explain what “convenience” features are available from the FZV key.
• Describe how the Seat Module communicates a request for a stored memory position
with the mirror modules.
• List what circuits are controlled by Consumer Cut Off.
• Demonstrate how to Emergency disarm DWA.
• Describe the changes in the 2000 MY Key.
• Explain the electronic influence on power steering assist (Servotronic).
• Demonstrate how to open the sunroof (in the event of an electrical malfunction).
CENTRAL BODY ELECTRONICS (ZKE III)
Models: E38 - 740i(L) and 750iL
E39 - 525i, 528i, 530i, 540i and M5
E53 - X5 3.0i and X5 4.4i
Production Date: E38 1994 to Present
E39 1997 to Present
E53 1999 to Present
Manufacturer: Hella
Pin Connectors: White - 26 pin, Black 26 pin, Black 20 pin (large)

Rear Window Wiper/Washer System (E39 Sport Wagon and E53): The system is
included in the scope of ZKE however is not controlled directly by the GM. The control elec-
tronics are integrated into the rear wiper motor assembly. The control electronics contains
two hall sensors, one for monitoring park position and other for the end stop, or to signal
reverse direction of the wiper motor. The control electronics are connected to the vehicle
electrical system via a single seven pin connector.
The rear wiper system is operator controlled
through the wiper stalk switch providing the fol-
lowing functions:
• Intermittent rear window wiping
• Programmed rear window wiping interval
• Operation of the rear window washer
Pressing the wiper stalk forward to the first detent activates the rear wiper in the intermit-
tent mode
. The timed interval is approximately 7-12 seconds. The full sweep and park posi-
tions are recognized by the two hall sensors on the motor gear assembly. If the wiper is
switched OFF, the wiper blade will return to the park position.
The programmed wiper interval procedure is as follows:
• Briefly switch the rear wiper ON/OFF
• Wait the desired interval time
• Switch the rear wiper ON again
• The OFF time will be the programmed interval - up to approx. 30 seconds
Rear window washing is activated by pressing the wiper stalk switch to the full forward
position.
The washer pump operates followed by two full wiping cycles. The wipers will then
switch to the intermittent wiping mode. Additionally, the system automatically controls the
following safety and convenience features:
• Wiper interrupt with the rear glass opened
• Wiping interrupt with a blocked wiper arm
• Continuous wiping when the vehicle is shifted into reverse
When the transmission is shifted into reverse, the wiper will switch to continuous operation
until the vehicle is shifted out of reverse. This signal (high) is provided by the LCM III when
it activates the back up lights.
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Central Body Electronics ZKE III
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Anti-Theft (DWA) System
Purpose of the System
The DWA alarm system offers vehicle protection by monitoring the doors, hood, interior,
luggage compartment and vehicle tilting. When activated, DWA deters theft by sounding
an alarm siren for 30 seconds, flashing the low beam headlights (high beam on Xenon
equipped models) and four way flashers for 5 minutes.
The control electronics for DWA are integrated in the general module. The DWA - LED
indicator is located in the rear view mirror (E38 in the top center IHKA grille).
The system is “armed/disarmed” from the driver’s door lock cylinder, remote transmitter or
luggage compartment lock cylinder. The alarm is immediately deactivated when disarmed
with the key in the driver’s door lock cylinder (may be deactivated in Conversion) or remote
transmitter.
The GM utilizes existing components and/or circuits as part of the DWA system:
• Door latch switch/sensor contacts (door open/closed).
• Trunk lid switch contact (monitored for closed trunk).
• Trunk lock key position switch (located on the trunk lock, this switch signal prevents
DWA from activating if armed when the trunk is opened with the key).
• Hood switch (monitored for closed hood, located under the hood).
• DWA status LED (part of rear view mirror).
The additional components required are:
• Interior Sensor • DWA Siren • Tilt sensor
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Central Body Electronics ZKE III
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Principle of Operation
DWA Arming/Disarming
• The DWA is armed every time the vehicle is locked from the outside with the door lock
cylinder or FZV key.
• The DWA LED flashes as an acknowledgment along with the exterior lights and a
momentary chirp from the siren.
• The GM monitors all required input signals for closed status (door closed, luggage com-
partment closed, etc.) The inputs must be in a closed status for a minimum of 3 sec-
onds for the GM to include them as an activation component. If after 3 seconds any
input signal not in the closed status is excluded (this is acknowledged by the DWA LED)
preventing false alarm activations. The hood switch can be “lifted” to the service posi-
tion to test the alarm with the hood open.
• If the DWA is armed a second time within 10 seconds, the tilt sensor and interior pro-
tection sensor are excluded as alarm activation components. This function is useful if
the vehicle is transported on a train or flat bed truck to prevent false alarm activations.
• While armed, the trunk can be opened with out the alarm being triggered as follows:
- If opened with the trunk remote button via the FZV, the GM prevents the alarm from
activating. (This feature is customizable under the Car Memory function).
- If opened with the key at the trunk lock cylinder the trunk key position switch sig-
nals the GM and in the same manner prevents the alarm from activating.
In either case, when the trunk is returned to the closed position, it is no longer con-
sidered as an activation signal.
Panic Mode Operation: When the trunk button is pressed and held, the GM is signaled
to activate the siren for the Panic Mode. The panic mode is function with either an armed
or disarmed DWA system.
Emergency Disarming: Emergency disarming occurs automatically if a key is used to turn
the ignition switch on and the EWS accepts it. The EWS signals the GM to unlock the doors
and deactivate the DWA.
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Central Body Electronics ZKE III

Power Windows/Sunroof
Purpose of the System
The features of the power windows and sunroof system include:
• One-touch operation in both directions (up/
down) on all four windows.
• The cable design window regulator is used
for all windows.
• Anti-trap detection is through the use of the
pressure sensitive finger guard.
• The control of the front window motors is
carried out in the respective door modules.
• The control of the rear windows is carried
out in the GM III.
• The switch block/module on the driver’s
door panel controls all four windows and the
rear window lock out feature.
System Components
- with the Principle of Operation
The signals from the switch block pass through
the driver’s door via the P-Bus and on to the
GM III and passengers door module.
Each window switch has four positions.
Two for the standard mode of operation:
• Push to first detent and hold to raise/lower
the window (1).
Two for the one-touch mode:
• Push to second detent and quickly release
(quick strike) to automatically raise/lower
the window (2).
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Central Body Electronics ZKE III
1
2
Rear Windows
Lock Out
Switch

All window operations signals are digital inputs to the door module and GM III.
• Comfort closing/opening of the windows from the driver’s lock cylinder. The remote key
provides opening only.
• When the ignition key is in accessory or “on” position press the switch to open or close
the windows. Window operation is possible with the ignition switched off until a front
door is opened or 16 minutes (maximum) has elapsed.
• Window load switching is through relays. The front window control relays are located in
the door modules, the rear window relays are in the GM III. The GM III monitors the cur-
rent draw for end limit position. The maximum run time for the window motors is limit-
ed to 6 seconds in the one-touch mode. This allows the motors to be switched off if the
end limit load sensing fails.
E53 Style Window Switches:The E53 power window switch design is a push - pull type
switch. Each switch provides the GM with the coded ground signaling strategy as previous
two wire switches.
Pushing a switch to the first detent and holding
provides
a single ground signal on one wire
requesting the GM to operate the window
motor in the down direction.
When released, the ground signal is removed
and the window motor stops.
Momentarily pushing the switch to the second
detent and releasing provides
an additional
ground signal on the second wire requesting
the “one touch mode”, operating the window
motor automatically.
The motor runs the window down until it reach-
es the end stop.
The switch functions in the same manner for
the upward run of the window motor but the
ground signal sequencing is reversed.
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Central Body Electronics ZKE III
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Interior Lighting
Purpose of the System
The GM controls the interior lighting automatical-
ly with the status change of several monitored
inputs. The lighting can also be manually con-
trolled using the interior light switch.
In addition to the various time controls, the inte-
rior lights are also subject to the 16 minute shut
down of the GM (consumer protection).
Principle of Operation
The interior light switch is a push button switch that will carry out the opposite command
of the current status of the lights. (ie: if the interior lights are currently on, pushing the but-
ton will switch the lights off.)
• If the interior lights are switched “ON” by the button with the ignition switched ON, the
interior lights will remain on until they are switched off by the button.
• If the interior lights are switched “ON” when the ignition is switched OFF, the lights will
remain on for 16 minutes (consumer cutout).
• Pressing the interior light button for longer than three seconds will switch the lights to
continuous off. This feature is intended for workshop use.
Pressing the button again will
return the lights to the normal operational status.
• Locking the vehicle from the outside will immediately switch off the interior lights.
The ON/OFF conditions for the interior lights in the automatic mode are as follows:
ON Conditions
• Door Open.
• Switching off ignition after exterior
lights have been switched off.
• MRS Control Module crash input.
• Unlocking with FZV or pressing FZV
lock button when the vehicle is
already locked (interior search fution).
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Central Body Electronics ZKE III
OFF Conditions
• All doors closed with ignition on.
• All doors closed with ignition off after 20
seconds.
• 20 seconds after switching off ignition with
lights off.
• 8 seconds after remote control activation.
• 16 minutes with door(s) open.
• When doors are locked.

System Components
Door Contacts: As mentioned in the Central Locking Section, the existing door contacts
opened/closed are also an input for the interior lighting function. The E53 uses the Hall
effect sensors for the purpose of monitoring door open/closed status (located directly
behind the rotary latch plate encased in the actuator). The sensor is activated by the rotary
latch plate's position.
• Door closed, the rotary latch plate is in the latched position. Current flow through the
hall sensor is < 5 mA.
• Door open, the rotary latch plate is in the open position. Current flow through the hall
sensor is > 12 mA.
A change in current flow informs the General module when a door is opened or closed.
Front Seat Interior/Map Light Unit:The overhead front seat interior light unit contains a
single main interior light. The light is controlled by the GM automatically or by momentarily
pressing interior light switch located on the light assembly.
The switch provides a momentary ground signal that the GM recognizes as a request to
either turn the light on (if off) or turn the light off (if on).
If the switch is held for more than 3 seconds, the
GM interprets the continuous ground signal as a
request to turn the interior light circuit off for the
Workshop Mode
.
The workshop mode is stored in memory and
will not come back on even if the GM is removed
from it's power supply and reconnected. The
switch must be pressed to turn the lights back
on.
There are two reading/map lights also located in the assembly. Each map light is mechan-
ically controlled by depressing the corresponding on/off switch. The power supply for the
map lights is supplied by the GM through the Consumer Cut Off circuit.
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Central Body Electronics ZKE III