SpaceStar (A00) Built 08-2020 has distance sensors on rear apron – without function

Good day to all SpSt owners, I have acquired a SpSt for my partner since the beginning of the year. Apart from the fact that there are no entries in the service booklet with almost 40Tsd kilometer performance, I have made the “strangely black” engine oil as the first maintenance measure. With this for me meaningless vehicle use – without maintenance- I start this topic start: On the rear bumper are igs. 5 distance sensors visibly installed. On the trunk floor the associated cables of the installed sensors are plugged in on a collector plug with alphabetical identifiers of the “tool content container”. However, the electronic connection to the on-board complputer is not given. When inserting the return gear, only a right/upside rear front mounted in front of the rear disc sounds annoyingly loudly according to beepending black housing of approx. 3x5cm size. What recommendations/tips can give me feedback about this already from the MitsubishiSpaceStar forum? As a DIY-bastler I would look forward to some advice, however, which can not be installed here, but can be used here.