Antitheft System III (DWA III)
Antitheft System III (DWA III):Functional Description:
Notes:
Depending on the model series, the Systems (e.g. infrared locking system) which interact with the DWA and which are referred to in the following information are partly installed as standard and partly available as optional extras.
Brief Description:
The task of the 3rd generation antitheft system (DWA III) is to detect attempts at breaking into and stealing the vehicle, to give audible and visual warning signals and to prevent the engine from being started by way of a starter blocking feature.
The DWA system additionally equipped with interior protection feature and inclination monitor protects the vehicle windows and prevents towing wheel theft.
The DWA system is switched on and oft (armed/disarmed) via the door locks or the infrared locking system.
System Components/Component Functions:
The antitheft system contains the following components:
- Electronic control unit (DWA III control unit): Control of all functions in the DWA system
- Status LED: Indication of current status of DWA system
- Antitheft horn: Audible warning signals
- External switches-Reed contacts: Monitoring elements
- Inclination monitor (optional extra): Additional protection for vehicle against wheel theft/jacking up or towing off
- Conductor loops in windows (optional extra): Interior protection, i.e. window monitoring
Note: Two versions of the DWA system are available: A basic version and a version with inclination monitor and interior protection facility (inclination monitor and interior protection facility are interconnected).
The control units of both versions therefore differ. The version with inclination monitor/interior protection can be recognized from the outside by the additional plug contact for this additional equipment.
The DWA system communicates with other systems:
- Central locking system
- Infrared locking system
- On-board computer (BC)
- DME
- Crash and alarm sensor
Scope of Functions:
The door locks and the infrared locking system serve as the operating elements for the DWA system (arm/disarm).
Monitored components are:
- Lock contacts driver's and passenger's door Rear lid
- Driver's door
- Passenger's door
- Rear doors Glove box
- Rear axle contact
- Radio
- Engine start
- Disconnection/connection of battery
- Front lid
- Vehicle tilt (only with inclination monitor)
- Driver's and passenger's window (only with interior protection)
- Rear window (rear screen) (only with interior protection)
- left-right rear windows (only with interior protection)
Function:
To arm (switch on) the DWA system, the ignition key is turned to the right in the door lock as far as it will go. The "arm" command is given to one of the operating elements (door lock or IRS system) by way of the transition to the "arm" position. Initially, this command is buffered by the DWA control unit. At
this point in time, the DWA system is set to "arm" mode.
The acknowledgment signal QZV (from the central locking system) serves as a synchronization signal for the lock contacts. The QZV signal ensures that all contacts perform the same command within a limited period of time (max. 50 ms). Lock signals triggered at different times represent a manipulation for the
monitoring logic for the DWA unit.
The "ready to arm" status is achieved when the QZV signal is applied continuously for at least 3 seconds. If the time of at least 3 seconds is not achieved, the DWA system cannot be armed and the "arm" Status is reestablished. The signal is ignored if the OZV signal has been received for 3 seconds and the DWA has
assumed the "ready to arm" status.
The system cannot be armed if one of the signals terminal "R", "15" or "61" (e.g. ignition switch "ON") is active. In this case, the "arm" command is not carried out by the system.
If, during the arming procedure, one of the elements to be monitored is not in the rest position (e.g. door open), the LED flashes until either all elements are in the rest position or the flashing time (approx. 10 seconds +/- 1 second) has elapsed.
The trigger blocking time (trigger = monitoring element/switch) of 3 seconds +/- 0.5 seconds is started with the transition to the "ready to arm" status. No trigger is monitored within this period of time so that no alarm can be triggered. Once the trigger blocking time has elapsed, all triggers at rest are
included in the alarm evaluation.
If a trigger moves out of the active position to the rest position (i.e. closed) after the trigger blocking time has elapsed, the trigger blocking time is restarted. The trigger blocking time now only applies to the triggers still not included in the alarm evaluation. In this way, alarms are prevented when lids
or doors are not immediately closed correctly. The LED is switched to a steady light with the "alarm" status.
If programmed as being installed, the inclination monitor is switched on with the "ready to arm" status.
The inclination monitor can be switched off for special purposes such as tilt garages, ship transport, car trains etc. For this purpose, after arming the DWA, the system must be armed once again within the following 10 seconds. This "subsequent arming" switches off the inclination monitor but the DWA system remains armed. As an acknowledgment signal for the driver, the status LED goes out for 1 second after "subsequent arming".
The command "disarm" is triggered at one of the operating elements (locks) by unlocking the vehicle; the vehicle is unlocked, the DWA system disarmed (switched off), the status LED goes out.
Logic of Status LED:
LED OFF: DWA disarmed or armed for longer than 36 h. LED is switched oft to save power when the DWA is armed for longer than 36 h. When the DWA is disarmed, the LED lights as an acknowledgment for 1 second.
LED flashes: An element to be monitored is not in the rest position or alarm has been triggered. The DWA is still armed.
LED ON: DWA system is armed.
Inclination Monitor (Optional Extra):
The inclination monitor represents an extension to the existing antitheft system. Its task is to detect tire/wheel theft or attempts at towing/jacking up the
vehicle, to transfer this information to the DWA control unit and to trigger an alarm.
The inclination monitor can register all changes in vehicle position (all directions). The inclination monitor contains an electrolyte whose electrical resistance varies dependent on the vehicle inclination due to the changed liquid level.
The inclination monitor is switched on and off by the DWA control unit. After the switch-on command (arm command) is given, the inclination monitor performs a self-test. The result of the self-test is signaled back to the control unit as an acknowledgment. The inclination monitor is switched on when the signal is
positive (inclination monitor OK.) and not switched on if the signal is negative. The current parked position of the vehicle is stored in the form of the component's longitudinal angle and transverse angle.
The inclination monitor compensates for drifting (soft base or change in temperature) and to a certain extent shaking of the vehicle. If the set values, including tolerance value, are exceeded in the transverse or longitudinal direction, the inclination monitor sends an alarm signal to the DWA control unit.
Note: The inclination monitor is active after a switch-on delay of approx. 10 sec.
Interior Protection (Optional Extra):
The interior protection facility provides glass breakage protection for the following windows: Rear window (rear screen), driver's and passenger 5 window, left and right rear windows, also the rear quarter light depending on the model.
The side windows which can be lowered are protected by means of Reed contacts: When the side window remains closed, the magnet mounted on the bottom edge of the window is positioned parallel with respect to the Reed contact so that the power circuit is closed. If the window is broken or opened by force, the magnet
moves away from the Reed contact and an alarm is triggered.
The fixed side windows are protected by contact loops attached to the relevant window. If the window is broken, the alarm is triggered by the open current circuit.
The rear screen is protected by the heating conductor of the rear window defogger.
The front screen is not monitored!
Note: To ventilate the interior of the vehicle, the side windows can remain open by a maximum of 10 mm also when the DWA system is armed with the windows
protected.
Installation locations: Control unit/inclination monitor:
DWA control unit: Under rear seat on left
Inclination monitor: Rear left of luggage compartment