A system for estimating an amount of soot in an exhaust particulate filter includes a delta P soot load estimate generator configured to generate a first soot load estimate as a function of a pressure drop and a mass flow of exhaust. The system further includes a model estimate generator configured to generate a second soot load estimate as a function of a modeled engine performance. A trust factor generator is configured to determine a trust factor signal as a function of at least one engine operating characteristic, and a decision generator is configured to determine whether to use the first soot load estimate or the second soot load estimate as a function of the trust factor signal.