PACCAR issued a recall on the T270, T300, T370, and T800 models

The emergency vehicle applications that are subject of this recall are designed with a dash-mounted switch that enables the vehicle operator to inhibit the aftertreatment diesel particulate filter regeneration in environments where the operator believes it may be unsafe for elevated exhaust temperatures. Due to an issue with the logic in the Electronic Control Module (ECM) software in certain vehicles, the switch may not function correctly, leading the operator to believe that the switch is in "inhibit" mode when, in fact, it is not. As a consequence, the operator may unknowingly permit hot exhaust gases to exit the vehicle tailpipe, increase the risk of melting or burning of nearby surfaces, or a fire, causing property damage, personal injury or death. Correction: Cummins dealers will upgrade the ECM software.