Abstract: A system 10 is provided for monitoring the loading of a diesel particulate filter 12. System 10 is adapted for use in combination with a vehicle including an internal combustion diesel engine 14 of the type having several substantially identical cylinders 16 which drivably rotate a crankshaft 17. Engine 14 includes an intake manifold 18 which selectively delivers air to cylinders 16, and an exhaust manifold 20 which selectively discharges exhaust gasses from cylinders 16. System 10 includes an engine control unit or controller 40 which is communicatively connected to a pressure sensor 42 that is operatively disposed in the intake manifold 18, and other vehicle operating conditions sensors 44. Controller 40 monitors the signals received from sensors 42 and 44, and based upon the received signals, estimates the loading of the DPF 12 and determines when the DPF 12 should be regenerated.