Method for diagnosing nitrogen oxide sensor in exhaust gas passage of internal combustion engine of motor car in workshop, involves washing nitrogen oxide sensor with air, and comparing output signal of sensor with reference value

摘要

The method involves washing a nitrogen oxide sensor (18) with air. An output signal of the nitrogen oxide sensor is compared with a predeterminable reference value. The air is delivered by a piston movement of an internal combustion engine (10). The piston movement is carried out via a test operation of the combustion engine, an operation of a starter when injection is switched off and a thrust operation of the combustion engine. A defect on the nitrogen oxide sensor is recognized. The combustion engine is provided with a cylinder (12), an air duct (14) and an exhaust gas passage (16).