Movement Sensor
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2009 Volvo S60, 2008 Volvo S60, 2007 Volvo S60, 2006 Volvo S60, and 2005 Volvo S60. However, it is still accessible from the selected car via links, so may be relevant.
The Mass Movement Sensor detects movement in the passenger compartment using radio waves at 2.450 GHz. The Doppler effect principle is used to determine if the frequency of the received microwave has been modified in comparison to the transmitted microwave. Any change in frequency is interpreted as a movement in the car. When movement is detected, a trigger signal is sent to the upper electronic module which activates the alarm.
The movement sensor is located in the headlining in the center of the car. This allows the sensor to cover as large an area as possible.
There are diagnostics for the movement sensor.