Object Detection Description and Operation (SOD): Notes

WARNING: This page is about a different car, the 2008 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.

The side object detection (SOD) sensors monitor and detect objects of interest in the vehicle blind spots or blind zones on each side of the vehicle. There is one SOD sensor on each side of the vehicle, the right and left sensor. Each SOD sensor monitors and reports objects of interest within a specified detection zone. The SOD system uses visual indicators located on both the right and left side rear view mirrors to alert the driver to the presence of an object of interest in the detection zone. The detection zone is the vehicle blind spot that may not be visible in the inside or outside rear view mirrors.

The SOD sensors use radar to detect objects of interest within the detection zones. The rear integration module (RIM) provides battery power to the SOD system. The two SOD sensors are setup in a configuration where the left sensor is the master sensor. The SOD right sensor is differentiated from the other SOD sensor by having an extra ground circuit terminal. Communication between the SOD system and the door module is via the master SOD sensor.

When the SOD system detects an object of interest on any side of the vehicle, the master SOD sensor sends a serial data message to the door modules to turn the SOD indicator ON. If the left or right turn signal is turned ON when an object is in the detection zone, the SOD indicator flashes to indicate that a vehicle is in the detection zone. The door module controls the SOD indicators located in the side rear view mirrors via a hard wire signal and ground circuit.

The SOD system will not operate if blocked by mud, dirt, snow, ice, slush or water from heavy rainstorms. Prior to performing diagnostic, clean both sides of the fascia and sensor of any contamination (mud, dirt, bumper stickers, labels, etc.). However, under normal circumstances (dry weather and clean fascia), if the SOD indicators do not light up consistently when the system is ON and vehicles are in the blind zone, the system may need service.

Occasional missed alerts can occur even under normal circumstances (dry weather and clean fascia). The SOD system does not need to be serviced due to an occasional single missed alert (i.e., when the SOD indicators do not activate with the system ON and a vehicle is in the blind zone). It is important to note that the number of missed alerts increases with increased rainfall and/or road spray due to water sheeting on the fascia. This happens when rain and road mist condition cause water sheeting to block the sensor transmission and does not mean that the sensors need to be serviced.

The SOD sensors maintain a history buffer of up to 16 SOD events which can be accessed using the scan tool. The history buffer captures sensor interactions with the driver and messages displayed in the DIC.

The SOD system consists of these main components:

Left SOD Sensor
Right SOD Sensor
Door Modules (Driver and Passenger)
Left and Right Outside Rear View Mirror

The SOD system has four operating states:

OFF: The SOD system is OFF and the ignition is OFF.

Disabled State: The SOD system is disabled by any of the following reasons:

The SOD system is disabled by the operator from the DIC vehicle information menu. The SOD system commands the DIC to display SIDE BLIND ZONE ALERT SYSTEM OFF message.
Loss of serial data communications. The SOD system commands the DIC to display SERVICE SIDE BLIND ZONE ALERT message when this condition exists.
An internal system malfunction. The SOD system commands the DIC to display SERVICE SIDE BLIND ZONE ALERT message.

Stand-by State: In this state the vehicle transmission is in PARK or the park brake is Set.

Monitoring State: The SOD system constantly monitors the detection zone.

Blocked State: The SOD system detects that either the left or right sensor is blocked by mud, snow or ice. When either of the SOD sensors are blocked, the SOD system commands the DIC to display CLEAN SIDE BLIND ZONE ALERT SYSTEM message. The SOD system operates normally when the blockage is removed.