According to the diesel particulate filter(DPF) fault type of blockage and leakage

exhaust resistance test and engine bench test were carried out to get the major fault characteristic parameters including exhaust gas flow

exhaust temperature and exhaust pressure. By comparing with the traditional pressure drop model

an orthogonal least squares method was applied to the DPF fault diagnosis

which allowed to form a DPF fault diagnosis method based on the orthogonal least squares model fitting and to use the collected major fault characteristic parameters to verify the feasibility of the method. By defining an error coefficient vector

the different fault areas formed from different DPF fault types in the generalized failure space were analyzed to provide a theoretical basis for the development of DPF fault diagnosis technology. The degree and type of failure

such as blockage and leakage

can be judged by analyzing the error coefficient vector. On the basis of this feature

the DPF diagnostics strategy can be established.