Interior Motion Sensor

When the vehicle is double locked, the interior motion sensor monitors for movement in the vehicle's cabin.

The interior motion sensor consists of a micro-controller, two acoustic transmitters and one acoustic receiver. The receiver and one of the transmitters face forward and the other transmitter faces rearward to ensure complete coverage of the vehicle's cabin.

The interior motion sensor is powered by a feed from the central junction box (CJB) and activates and de-activates the interior motion sensor. When the interior motion sensor is active it outputs ultrasonic pulses from the transmitters and checks the echoes picked up by the receiver for changes to the passenger compartment profile. If it detects a change of profile, indicating movement in the passenger compartment, the interior motion sensor reports the alarm to the central junction box (CJB).

Each time the interior motion sensor is armed, it performs a self test. If there are no faults the interior motion sensor sends an acknowledgment signal to the central junction box (CJB). If the central junction box (CJB) does not receive the acknowledgment signal it de-activates the interior motion sensor.