Circuit/System Description
WARNING: This page is about a different car, the 2015 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
The side detection system uses two modules B218L Side Object Sensor Module - Left and B218R Side Object Sensor Module - Right. The left module is the master and is on the vehicle's serial data bus and communicates to the right module on a private bus. The internal fault detection is handled inside the B218L Side Object Sensor Module - Left. No external circuit diagnosis is involved.