Theory Of Operation
WARNING: This page is about a different car, the 2012 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.
The Variable Geometry Turbocharger (VGT) is electronically activated by the Turbo Actuator. The Turbo Actuator is a smart device that receives information via the J1939 Datalink from the Powertrain Control Module (PCM). The Turbo Actuator performs its own diagnostics and reports failures back to the PCM over the J1939 Datalink.