Internal combustion engine's i.e. diesel engine, operation diagnosing method for vehicle, involves detecting error when consumption of reduction unit exceeds threshold value, where consumption is compared with another threshold value

摘要

The method involves determining offset between a set point for exhaust gas recirculation rates and an actual value for the recirculation rates in an operational condition of an internal combustion engine i.e. diesel engine (1). The offset is compared with a predetermined threshold value to determine consumption of a reduction unit. Consumption of the reduction unit is compared with another predetermined threshold value, and an error is detected when the offset exceeds the former value. Another error is detected when the consumption of the reduction unit exceeds the latter value. An independent claim is also included for a device for diagnosing operation of an internal-combustion engine.