Component Tests and General Diagnostics

CHECKING FUNCTION OF OXYGEN SENSOR





- Unscrew plug (1).
- Screw in Special Tool 13 0 100 and attach the Special Tool 13 0 090.
- Connect the BMW service tester





- Measure the CO level
- Specifications: 0.2 to 1.2% by volume.





- Pull off vacuum hose (1) on the pressure regulator and plug.
- The CO level will rise briefly and is immediately regulated back to the original value = the oxygen sensor is working.

If Not:
- Check the power supply to the oxygen sensor from the relay according to the wiring diagram.