On some 2016 GMC Sierra vehicles equipped with a 6.6L diesel engine, an exhaust gas temperature sensor at the position two location may have failed. If this occurs, the control system will inhibit diesel particulate filter regeneration and selective catalyst (Diesel Exhaust Fluid) dosing.
The Service Exhaust Fluid System or Service Emission System message will be displayed, the MIL will be on and a DTC related to the position two exhaust gas temperature sensor will be set.
In the course of following SI-based diagnostics for the DTC, you may determine that the fix is to replace the exhaust temperature position sensor in position two.
