Page 38 of 80

The siren has four wires connecting it to the system; KL 30, KL 31, activate siren signal
(SIRENE) and the arm/disarm signal (STDWA).
The arm/disarm output signal from the GM is provided to the Tilt sensor, FIS/UIS sensor
and the siren. The arm/disarm signal is a switched ground that signals the components of
an armed/disarmed status.
The activate siren signal to the siren is high whether DWA is armed or disarmed. If a mon-
itored 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
“SIRENE” signal as suddenly going low, the siren is activated.
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Central Body Electronics ZKE III
SIRENE
STDWA
97 MY E38 Shown
Page 40 of 80

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
Page 41 of 80

Alarm Indication
When the alarm is triggered, the siren will sound for 30 seconds. At the same time the low
beam headlights (high beams on Xenon equipped vehicles) and four way flashers for 5 min-
utes. The GM signals the LCM via the bus system to flash the lights.
Following an alarm activation, the system will reset and activate again if further tampering
occurs.
DWA LED Status:
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41
Central Body Electronics ZKE III
DWA STATUS DWA LED CONDITION
Disarmed OFF
Armed Continual slow flash
Armed with one or more monitored Rapid flash for 10 seconds,
inputs not in closed position then continual slow flash.
(ie: trunk not fully closed, etc)
Alarm activated Rapid flash for 5 minutes,
then continual slow flash.
Rearmed in less then 10 seconds. ON for 1 second
Disarmed after activated alarm Rapid flash for 10 seconds,
then OFF.
Page 76 of 80

Sleep Mode
To lower the constant battery draw when the vehicle is parked, the complete ZKE system
will go into the “Sleep Mode” 16 minutes after the ignition has been switched off and no
further ZKE function is active.
For example, the approximate E39 (528i) Battery draw is:
• Ignition switch off = approx 750 mA.
• One minute after = approx. 560 mA.
• After 16 minutes (sleep mode) = approx. 18 mA.
All modules in the ZKE system will go into the sleep mode. The P-Bus remains active, how-
ever no data transfer takes place until a wake-up request is received. The general module,
door modules or keyless remote module can wake the system up and put the ZKE back
on line. The K-Bus is active (high) in the sleep mode.
Sleep Mode Criteria:
KL R, KL 15 OFF and no further function activated for 16 minutes.
Wake Up Criteria:
KL R or 15 “ON” or a change in one of the signals listed below.
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Central Body Electronics ZKE III
SIGNAL ACTIVITY ORIGINATING
MODULE
K-BUS High General Module
Door jamb switches (possibility of 4) Low “
Trunk lid lock cylinder microswitch High “
Trunk lid pushbutton microswitch Low “
Interior Trunk lid pushbutton microswitch Low “
Central locking button Low “
Hood microswitch Low “
Trunk Lid microswitch Low “
Interior light switch Low “
FIS sensor Low “
Tilt Alarm sensor Low “
FBZV operational signal High FBZV Module
Driver’s door lock microswitch - (lock) High PM-FT/SB
“ “ “ “ - (unlock) High “
Passenger door lock microswitch - (lock) High PM-BT
“ “ “ “ - (unlock) High “