Theory Of Operation

The Powertrain Control Module (PCM) monitors the soot load in the Diesel Particulate Filter. The soot load in the Diesel Particulate Filter is estimated by the PCM using the Exhaust Differential Pressure Sensor values and the calculated soot output of the engine. Under normal operating conditions the Diesel Particulate Filter is self-cleaning, where accumulated soot is converted to ash. Under light load operating conditions, the driver may be notified via the vehicle's EVIC message center that it is necessary to modify the vehicles driving routine/duty-cycle (see Owner's Manual for details) in order to allow the Aftertreatment Diesel Particulate Filter system to self clean.