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CENTRAL LOCKING
SYSTEM FEATURES:
• The Central Locking system controls the door locks, tailgate locks and Fuel Filler Flap
actuators.
• The familiar single/double locking strategy is maintained from previous systems with a
new style door lock mechanismcombined with dual actuator motors similar to that
of the E46 ZKE V system.
• The automatic locking feature activates the door lock actuators when a road speed
signal of 7.5 MPH is detected via the K-Bus. The factory default encoding of this
feature is off, but can be encoded on for individual users with the Key Memory function.
• The Driver’s door lock location is the only point outside of the vehicle where the key can
mechanically control the central locking system functions. The lock incorporates the
familiar overrunning lock cylinder that breaks away and freewheels if an attempt is made
to destroy the lock with a screwdriver, dent puller, etc.
• The selective unlocking feature is maintained. A single unlock request from the driver’s
door with the key or via the remote transmitter unlocks the driver’s door only. A second
unlock request unlocks the remaining doors and trunk. This feature can be modified
for individual users with the new Key Memory capabilities to activate all lock actuators
simultaneously.
• When unlocked, the X5 uppertailgate can be opened by:
- the tailgate button in the center console SZM,
- trunk release switch pad located above the license plate, or
- the trunk release button on an FZV key.
• With the upper tailgate open, the lower tailgate is then opened by depressing the switch
located along it’s top edge.
• GM and EWS 3.3 interface via the K bus to monitor double lock status and to initiate
double lock override. This feature allows the doors to be opened from the inside if an
accepted EWS key is switched on in the ignition when double locked.
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CENTRAL LOCKING BUTTON
The central lock button in the center console
provides a momentary ground input signal to the
GM.
• This input initiates a single lock for each door
and the trunk.
• The fuel filler flap remains unlocked for
refueling purposes.
• If a door is manually opened while centrally
locked, the remaining doors stay locked.
The opened door can be re-locked when closed by manually locking or pushing the central
button twice. This allows the locks of the remaining doors to be re-synchronized again.
As an additional safety feature, the central lock button input also unlocks a double locked
system. Pressing the button returns the system to central lock (single) position, allowing
the doors to be opened when the interior door handles are opened twice. This feature was
also added to other ZKE systems during the 1999 model year.
CRASH SIGNALLING
The Multiple Restraint System (MRS III) provides a switched signal to the GM in the event
of an accident. The signal is an output function of the MRS control module and becomes
active when MRS determines a crash has occurred.
When active, the GM unlocks the door lock actuators, switches on the interior lights and
signals the LCM III via the K bus to activate the hazard warning flashers.
Once the crash signal is active, the GM will not respond to lock requests from the system
until the ignition switch is cycled or a front door is opened.
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POWER WINDOWS
The power window operation on the E53 is similar to previous systems. Features of the
system include:
• Control of the front and rear door window motors is carried out directly by the GM.
• One-touch operation in both directions on all four windows.
• Cable type window regulator used for all windows.
• Anti-trap detection is provided by the pressure sensitive finger guard .
• Push/pull window switches
• The rear window switches located in the rear doors can be deactivated by the pressing
child lock out switch in the center console.
• Convenience closing/opening of the windows from the driver's lock cylinder or
convenience opening only from the FZV remote key (FZV operation can be owner
customized with the Car Memory Function).
• Window operation with the ignition switched off until a door is opened or 16 minutes has
elapsed after the key is switched off.
• Window load switching is through relays integral of the GM for rear windows and in the
respective door switchblock modules for the front windows. The current draw is
monitored for end limit position. The maximum run time for the window motors is limited
to 8 seconds. This allows the motors to be switched off if the end limit load sensing fails.