Triggering Alarm Via Interior Motion Sensor

Alarm triggering via IMS[IRS]
The interior motion sensor relies on an ultrasonic sensor and is activated approx. t = 30s after the vehicle is locked. The sensor is installed in the interior motion sensor transmitter and receiver (A26/14).

When an alarm is triggered the overhead control panel control module (N70) transmits the alarm over the CAN-B to the rear SAM control module with fuse and relay module (N10/2).

The ultrasonic sensor works as a motion detector. When activated, it emits ultrasonic signals throughout the interior compartment of the vehicle (no special orientation). The reflected signals are picked up by the ultrasonic sensor, amplified and finally interpreted by a microcontroller.

The decision to trigger the alarm is based on the duration and speed of the movement.


NOTE: The IMS[IRS] function can trigger an alarm no more than three times in succession. After this the ATA[EDW] must be reactivated in order for this function to operate.


NOTE: In model 203.2 the left rear window glass breakage sensor (B39), the right rear window glass breakage sensor (B39/1) and the rear window glass breakage sensor (B39/4) (also in model 203.7) are connected to the interior motion sensor transmitter and receiver (A26/14). The glass breakage sensors are activated and their data interpreted by the interior motion sensor transmitter and receiver (A26/14).


The TS[AS]/IMS[IRS] switch with ATA[EDW] function display (N721/s7) located in the overhead control panel control module (N72/1) can be used to deactivate the interior motion sensor and/or the anti-towing sensor if, for example, passengers or animals are to remain in the vehicle. The interior motion sensor/anti-towing sensor is automatically reactivated during the next locking sequence unless the pushbutton switch is pressed beforehand.


NOTE: When the trunk lid is opened by means of the remote trunk release (RTR[HDF]), alarm triggering via the IMS[IRS] will not occur as long as the trunk lid is open.