Module, Blind Spot (BSM): Operation

WARNING: This page is about a different car, the 2020 Chrysler 300 and 2019 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) smart sensors are known as the Left Blind Spot Sensor (LBSS) and the Right Blind Spot Sensor (RBSS) are each controlled by their on-board microcontroller and control circuitry. When the microcontroller recognizes that the appropriate conditions exist, it will energize the sensor to generate 25 Gigahertz radar pulses through the blind spot zone on that 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 microcontroller.

The microcontroller analyzes the sensor data to determine whether any detected objects should be reported. When it is determined that an object should be reported, the microcontroller sends electronic request messages over the Controller Area Network-Interior High Speed (CAN-IHS) data bus to its respective Driver Door Module (DDM) or Passenger Door Module (PDM). The DDM or PDM then controls its respective left or right BSM display directly through a hardwired output. The microcontroller 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.

Each of the two BSM smart sensors are independent and communicates on the CAN data bus. The sensor performs a bulb test by requesting illumination of the triangle icon in its respective right or left blind spot display for a few seconds each time the status of the ignition transitions to ON. Each sensor microcontroller also continually monitors the BSM system and the sensor circuits and will store a Diagnostic Trouble Code (DTC) for any fault that is detected.