Blind Spot Sensor - Operation

OPERATION

The Blind Spot Monitor (BSM) Radio Detection And Ranging (RADAR) smart sensors 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 24 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 controls its respective left or right BSM display directly through a hard wired output and sends electronic request messages over the Controller Area Network (CAN) data bus to the Radio Receiver Module (RRM) (also known as the radio or head unit) 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 is independent and communicates on the CAN data bus. The sensor performs a bulb test by illuminating the triangle icon in its respective right or left blind spot display for a few seconds each time the status of the ignition switch 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.

The hard wired circuits between the BSM smart sensor and the display may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the BSM sensors or the electronic controls and communication between other modules and devices that provide some features of the BSM system. The most reliable, efficient and accurate means to diagnose the BSM smart sensors or the electronic controls and communication related to BSM system operation requires the use of a diagnostic scan tool. Testing and Inspection.