battery location BMW X5 2003 E53 Central Body Electronics Workshop Manual

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TILT SENSOR
Located in the electrical carrier forward of the glove
box, the tilt sensor is an electronic sensing device with
the sole purpose of monitoring the vehicle's parked
angle when DWA is armed.
The sensor requires three signal wires to perform its function:
• KL 30 - Constant battery voltage
• Signal "STDWA"; switched ground input signal provided by the GM indicating DWA
armed/disarmed status. The tilt sensor is used as a splice location for the STDWA sig-
nal to the Siren and FIS interior protection sensor.
• Signal "NG"; switched ground output signal provided to the GM. The signal is used for
two purposes,
1. As a momentary acknowledgment that the tilt sensor received STDWA and is cur-
rently monitoring the vehicle angle.
2. If the tilt sensor detects a change in the vehicle's angle when DWA is armed, signal
NG is switched to inform the GM to activate the siren.
When the tilt sensor receives the STDWA signal from the GM it memorizes the vehicle's
parked angle. The angle of the vehicle is monitored by the solid state electronics. Once
armed, if the angle changes, the tilt sensor provides a switched ground signal to the GM to
activate DWA.

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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