Module, Blind Spot (BSM): Operation

WARNING: This page is about a different car, the 2021 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.

The Blind Spot Monitor (BSM) Radio Detection And Ranging (RADAR) sensors are also known as the Left Blind Spot Sensor (LBSS) and Right Blind Spot Sensor (RBSS). When the micro-controller recognizes the appropriate conditions exist, it will energize the sensor to generate 25 Gigahertz radar pulses through the blind spot zone on the affected side of the vehicle. The sensor receives and filters the radar signals being returned from any objects detected within the zone, then transmits the appropriate data identifying the position and speed of identified objects to the micro-controller.

The micro-controller analyzes the sensor data to determine whether any detected objects should be reported. When it is determined that an object should be reported, the micro-controller sends messages over the Controller Area Network-Interior High Speed (CAN-IHS) bus to the Driver Door Module (DDM) or Passenger Door Module (PDM). The DDM or PDM then illuminates the BSM display through a hard-wired output. The micro-controller of the LBSS or RBSS also sends electronic messages to the radio to mute any current output through the sound system speakers and to generate chime tones as an audible alert.

The LBSS and RBSS both communicate on the CAN data bus. Whenever the ignition status transitions to ON position, both sensors request the brief illumination of the triangle icon in its respective blind spot display.