Action in service

An active test is activated automatically after this fault (secondary fault in fault code memory!)

1. Read out result of active test (are there still other fault codes stored in the fault code memory?=> continue here!)
2. Initiate system test for interchanged oxygen sensors. Follow system test instructions.
3. If system test returns no result, then
4. Visual inspection of lines and connectors
5. Measure lines
6. Replace lines or connectors if necessary
7. Check exhaust system upstream of oxygen sensor after catalytic converter for leaks
8. Change oxygen sensor after catalytic converter
9. Change oxygen sensor before catalytic converter
10. Replace control unit