Side Blind Zone Alert System
By techarchive on October 1, 2008 8:55 PM | No Comments
Lane-change accidents are caused by blind spots created by vehicle architecture, mirror resolution and a driver's physical capability to accurately assess a vehicle's presence, closing rate of speed and distance. Drivers changing lanes unaware of adjacent vehicles are the source of many near collisions every dayÂ*(fig. 1). They are also the source of numerous damaged vehicles and injured people in North America each year.
Introduced in the 2008 model year, Side Blind Zone Alert (SBZA) is an increasingly available option for a number of higher-end GM vehicles including the new 2009 full size trucks. Side Object Detection (SOD) is another term sometimes used for this feature.
By appropriately illuminating amber icons in the outside rear view mirrors, this supplementary system alerts drivers to the presence of other road users as they pass through the vehicle's left and right side blind spotsÂ*(fig. 2). An icon will flash to heighten the alert when turn signals are active on that side of the vehicleÂ*(fig. 3).
IMPORTANT:Â*SBZA is only a lane changing aid and does not replace driver vision. SBZA does not detect vehicles which may be rapidly approaching outside the side blind zones,
or pedestrians, bicyclists, or animals.
The system is relatively simple. Sensors are located behind the left and right rear fascia sides. They scan adjacent road lanes and control their corresponding mirror alert icons by GMLAN serial data communication to the door zone modules. In turn, the door zone modules switch power to the LED indicators within the mirrors.
SBZA can be turned on and off through a Driver Information Center (DIC) menu selection
or an option on the navigation screen. The DIC also alerts the driver to 'SBZA unavailable' and 'needs service' conditions.
The SBZA unavailable message occurs when sensor performance is degraded by the presence of water and is typically triggered by rain, snow, mud or ice. If the system does not self-recover once dry conditions have apparently returned, check that the sensors are clean and no labels are present on either side of the fascia.
As described in the owner manual, occasional false alerts on roadside infrastructures (such as guardrails, vegetation, etc.) or missed alerts are not service issues and are within normal operation.
TIP:Â*Because a trailer can interfere with the system's operation and the detection zones do not alter when a trailer is attached, it's preferable to switch the system off when towing.
TIP:Â*Always use the same part number when a replacement has to be made. Left and right sensors are identical and must always have the same part number. A harness ground connection automatically configures sensors for right hand side operation.
TIP:Â*To avoid VIN mismatch lock-out problems, do not substitute parts from other vehicles.
Scan tools can be used to check DTCs on either sensor. History DTCs may indicate an intermittent condition and should be approached accordingly.
A DIC service SBZA message shortly after the mirror icons have completed their vehicle power-on bulb check generally indicates a current DTC. Door zone modules should be investigated if the bulb check fails.
TIP:Â*Although often tied together in option packages, SBZA and Lane Departure Warning (LDW) are separate systems and should be treated as such. And as always, check for the latest service information and bulletins.
- Thanks toÂ*Simon Tong
