Circuit/System Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2015 GMC Yukon XL, 2015 GMC Yukon, 2015 Chevrolet Tahoe, 2015 Chevrolet Suburban, and 2015 Cadillac Escalade ESV. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition is turned ON, the control module receives the vehicle identification number (VIN) from the body control module (BCM). The control module will compare the VIN received to the VIN stored in memory.