Circuit/System Description (ROS)
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The inflatable restraint sensing and diagnostic module (SDM) stores a 4-digit primary key for the inflatable restraint vehicle rollover sensor (ROS). The SDM sends the ROS the primary key. If the ROS determines that it is the wrong primary key, the ROS will set DTC B1001 and send the SDM a vehicle mismatch message. The SDM then will set DTC B0090 3A and illuminate the SIR Warning Indicator. The ROS does not use a secondary key.