Antitheft Alarm System

Antitheft Alarm System

Functional description, see BMW Technology:
TIS -> Documents> SI Technology -> 61 09 03 (031)

Notes on function
The DWA electronics are integrated on the ultrasonic signal/interior sensor control module. They evaluate the signals relevant to the alarm system and decide whether the alarm should be triggered. The control module is connected to the data bus K-CAN SYSTEM, across which it receives the signals of the door modules and CAS and body base module control modules. In addition, a separate DWA data bus is connected to the control module, across which the signals between the DWA electronics and the control module emergency siren/inclination sensor (SINE) are transferred.

The inclination sensor and the emergency siren are grouped as one component. They are linked to the DWA electronics across the DWA data bus.

The inclination sensor monitors the horizontal and vertical position of the vehicle and issues an alarm signal in the case of a position change.

The emergency siren emits an acoustic alarm if required. The alarm is triggered when the siren receives a corresponding command from the DWA electronics.

In addition, an alarm is triggered independently of the DWA electronics under the following conditions:
- Emergency siren is disconnected from the vehicle electrical system
- Disconnection of the vehicle battery
- Rapid discharge of the vehicle battery
- Overvoltage in the vehicle electrical system (voltage > 16 V)

So that the emergency siren can operate independently of the vehicle battery, it is given a rechargeable battery that is charged when the engine is running.

In accordance with country-specific legislation, the emergency siren can be coded for an interval or intermittent tone.

In addition to the alarm trigger, the emergency siren can issue an acoustic acknowledgment signal on arming or disarming. This function can be coded depending on country.