Powertrain Expansion Bus
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
The ECM has an additional CAN bus, the powertrain expansion bus. The following components are integrated the Recuctant Control Module, the Nitrogen Oxides Sensor 1, the Nitrogen Oxides Sensor 2 and the ECM.