warning BMW X5 2005 E53 Central Body Electronics Workshop Manual

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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.

ALARM SIREN
The siren is located in the vehicle cowl
on the driver’s side of the vehicle. This
location provides a secure position with
loud acoustic output.
The siren contains electronic circuitry
for producing the warning tone when
the alarm is triggered. The siren also
contains a rechargeable battery that is
used to power the siren when the alarm
is triggered.
The rechargeable battery will allow the siren to sound if it or the
vehicle’s battery is dis-connected. The siren battery is recharged,
from the vehicle’s battery when DWA is not in the armed state.
The siren has four wires connecting it to the system; KL 30, KL 31,
Signal STDWA (arm/disarm signal from GM), and Signal NG (acti-
vate siren output signal to the GM)
The arm/disarm output signal from the GM (STDWA) is provided to the Tilt sensor, FIS sen-
sor and the siren simultaneously. The arm/disarm signal is a switched ground that signals
the components of DWA armed/disarmed status.
The activate siren signal (NG) is high whether DWA is armed or disarmed. If a monitored
input activates the alarm, the high signal to the siren is switched to a 50% duty cycle at
the GM. The control circuitry in the siren activates the siren driver. If the DWA is armed
and the battery is disconnected the siren recognizes the normally high “NG” signal as sud-
denly going low, the siren is also activated.
SIREN INSTALLATION
POSITION
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