A method for correcting an indicated engine output torque

A method for correcting an indicated engine output torque for a motor vehicle powertrain that includes a diesel engine 10, a particulate filter 11 and a torque converter 14 is disclosed in which the method includes estimating a magnitude of torque being transmitted from the engine1O to the torque converter 14 while regenerating the particulate filter 11, determining a reference magnitude of current engine torque being produced while regenerating the particulate filter 11, determining a torque error from a difference between the estimated magnitude and the reference magnitude, recording the torque error, determining a current torque error from the recorded torque error using a current engine speed Ne and a current reference engine torque as indices to the recorded engine toque error, producing a corrected engine torque from the sum of the current torque error and the current reference engine torque and using the corrected engine torque to control operation of the powertrain.