E63/E64 Microwave Sensors
Installation location
The anti-theft alarm has 4 microwave sensors. 2 microwave sensors are installed on the inner door panel of the driver's door and front-passenger door. 2 additional microwave sensors are installed on the inside of the B-pillars.
| Key | Explanation | Key | Explanation |
|---|---|---|---|
| 1 | Microwave sensor, front (example: front-passenger door) | 2 | Inner door panel |
| Key | Explanation | Key | Explanation |
|---|---|---|---|
| 1 | Microwave sensor, rear (example: passenger side) | 2 | B-pillar |
Construction
Each microwave sensor consists of the following components:
- Transmitter unit
- Receiver unit
- Interface to sub-bus for anti-theft alarm
- Internal circuit for 5-volt power supply
Pin Assignment Of 4-Pin Connector On Microwave Sensors
| Sensor (Connector) | Installation location | Pin 1 | Pin 2 | Pin 3 | Pin 4 |
| 1 (X14144) |
Front right | 12 volts (V) | 12 volts (V) | Earth (M) | Sub-bus for DWA (E/A) |
| 2 (X14146) |
Rear right | 12 volts (V) | Earth (M) | Earth (M) | Sub-bus for DWA (E/A) |
| 3 (X14145) |
Rear left | 12 volts (V) | --- | Earth (M) | Sub-bus for DWA (E/A) |
| 4 (X14143) |
Front left | --- | 12 volts (V) | Earth (M) | Sub-bus for DWA (E/A) |
| E/A = Input and output | |||||
| M = Earth | |||||
| V = Supply | |||||
| For current specifications regarding pin assignment, please refer to BMW diagnosis system | |||||
The different pin assignments serve as an identifying feature for the individual microwave sensors via the interior monitoring function.
How it works
The microwave sensor is a movement detector. The microwave sensor detects movement and the direction of movement (changes in distance) in the entire vehicle interior. The range/sensitivity of the microwave sensors is pre-set (depending on vehicle model and equipment).
3 seconds after the last door or hatch is closed, the microwave sensor starts its reference run. During the reference run, the vehicle interior is "scanned". This allows any changes in the vehicle interior (e.g. objects left on the rear seat) to be recognized. A self-test monitors the correct functioning of the microwave sensors. The microwave sensors are operational 20 seconds after the start of the reference run.
The 4 microwave sensors monitor the vehicle interior in zones. For this, the vehicle interior is divided into in 4 quadrants. The microwaves disperse in the shape of a sphere.
The DWA control unit actuates the microwave sensors in the following order:
| Key | Explanation | Key | Explanation |
|---|---|---|---|
| 1 | Microwave sensor in front-passenger door | 2 | Microwave sensor, rear right |
| 3 | Microwave sensor, rear left | 4 | Microwave sensor in driver's door |
The microwave sensors work in a frequency range of approx. 2.5 GHz. The microwave sensor uses the Doppler effect (Christian Doppler 1803-1853) to create the alarm trigger signal.
The DWA control unit in the emergency power siren evaluates the signals from the microwave sensor and triggers the alarm.
The emergency power siren for the acoustic alarm is actuated. The signal for the visual alarm is fed to the light module through the K-CAN.