Diagnostic Overview
Cummins fault code 2963 is commonly related to aftertreatment temperature sensing or exhaust temperature rationality. The ECM relies on exhaust gas temperature sensors to manage regeneration, protect the DPF and SCR, and confirm that aftertreatment temperatures are within range. Causes can include a failed exhaust temperature sensor, damaged wiring, loose connector, exhaust leak near the sensor, incorrect sensor installation, or abnormal exhaust temperature caused by another engine issue. Diagnosis should compare cold and hot live data, inspect the harness, and verify that the sensor is installed in the correct location.
