Theory Of Operation

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

The Blind Spot Monitor (BSM) system has two primary components; a Left Blind Spot Sensor (LBSS) and Right Blind Spot Sensor (RBSS). Each sensor includes an internal microprocessor that monitors and controls both the sensor and the blind spot indicator. The two sensors are concealed behind the outboard ends of the rear bumper fascia.

The microprocessor analyzes the sensor data to determine whether any detected objects should be reported. When it is determined that an object should be reported, the Sensor busses over the request to turn on the blind spot warning light on the Outside Rearview Mirror. The sensor also sends an electronic request message over the CAN IHS Bus to the radio. The Radio then mutes any current output through the speakers and generates a chime as an audible alert.

Each sensor performs a bulb test by illuminating the triangle icon in the Outside Rearview Mirror at each ignition ON cycle.