Instrument Panel, Gauges and Warning Indicators: Description and Operation: Overview

Warning Devices

Overview - Blind Spot Monitoring System
Eliminating blind spots is a major element in vehicle body design, but because of the structural requirements of B, C and D pillars, blind spots cannot be entirely eliminated. Statistics show that some accidents are directly attributable to drivers moving across into the path of overtaking vehicles that have not been seen in conventional mirrors. New mirror designs have improved the situation, but by remotely covering areas that cannot be seen either directly or by the vehicle mirrors, have led to the introduction of a radar-based blind spot monitoring system.
The blind spot monitoring system comprises:
- LH (left-hand) Blind spot monitoring sensor
- RH (right-hand) Blind spot monitoring sensor
- LH (left-hand) door mirror
- RH (right-hand) door mirror
The system uses two radar modules operating at a frequency of 24 GHz and each combining the radar face and electronic module in a single unit. The modules are located behind the rear bumper surface, symmetrically, one on each side of the car behind the rear wheels. They are side facing and inclined rearwards at an angle of 25 degrees, which is dictated by the shape at the rear of the vehicle. Each module is calibrated to detect a vehicle in the driver's blind spot. Once a vehicle is detected the module illuminates an amber warning 'alert icon' LED (light emitting diode) in the relevant exterior door mirror. If there is a fault or blockage with the blind spot monitoring system an amber warning status icon indicator dot LED (light emitting diode) is displayed in the exterior mirror and the message 'blind spot monitoring not available' or 'blind spot sensor blocked' is displayed in the instrument cluster message center.
When the system initiates, it performs a self-check, during which the warning icons in the mirrors illuminate alternately for a short period of time. Each module does a left/right determination check when the ignition is switched on. Each mirror has a different circuit configuration so that the modules can determine which mirror they are connected to. If a module detects the wrong mirror it will go into a fault condition.
The blind spot monitoring modules receive vehicle speed on the medium speed CAN (controller area network) and are inactive until the vehicle reaches 16kph (10mph).
Each Blind Spot Monitor module emits a radar field greater than the blind spot area. The actual blind spot area is calibrated into the module during its manufacture.

CAUTION: The blind spot monitoring system is designed as a driver aid not a safety device. The driver should always exercise due care and attention whilst driving.