Oxygen Sensor

Oxygen Sensor:

Check function:

•D• 200 - The prerequisite for carrying out this test is that the oxygen sensor must be at operating temperature. The indicated voltage signal is picked off in steps and fluctuates between 0.02 and 0.85 V.

When the oxygen sensor is not in operation, or a wire to the DME control unit has a break, a constant value of 0.45 V is indicated. This value is also indicated when no oxygen sensor is installed.

An oxygen sensor may be defective (e.g. due to deposits) and still indicate the required voltage signals. An indication for such cases is COmeasured values deviating from the nominal value despite the emission control system being active. Test option: Disconnect DME control unit from the voltage supply for at least 5 minutes. Then disconnect the oxygen sensor and perform CO measurement once again. If the CO value approaches the nominal value, the oxygen sensor should be replaced and CO measurement repeated.