A system and method are disclosed for controlling the temperature of an aftertreatment system, the method including interpreting an aftertreatment indicating temperature, determining that an engine fueling requirement is zero, and disengaging the engine from a transmission in response to the aftertreatment indicating temperature falling below a first threshold value and in response to the engine fueling requirement being zero, where the engine and the transmission comprise a portion of a vehicle powertrain. Alternatively, the method may include interpreting an aftertreatment indicating temperature, determining that an engine fueling requirement is zero, and performing a reduced air flow operation through the engine in response to the aftertreatment indicating temperature falling below a first threshold value and in response to the engine fueling requirement being zero.