DIAGNOSTIC DEVICE FOR EXHAUST PURIFICATION SYSTEM FOR REDUCING NOx

摘要

With this diagnostic device for an exhaust purification system for reducing NOx, in a state where a DPF over-accumulation lamp (34) is not lit, when a DPF regeneration start switch (35) has been operated (S2, 4), manual regeneration of a DPF (18) is started (S12) on the basis of determination that repair, based on a malfunction diagnosis, of the exhaust purification system for reducing NOx is complete and function confirmation has been requested. The temperature of an SCR catalyst (20) positioned on the downstream side of the DPF (18) is caused to rise due to the manual regeneration, and on the basis of the values of the SCR catalyst (20) on the downstream side detected by a NOx sensor (36), the diagnostic device confirms function recovery of the exhaust purification system for reducing NOx (S18-22).