P1155

P1155

Oxygen Sensor Ahead Of TWC, Bank 2 - Above Limit

Diagnosis conditions
- Exhaust temperature between 250 °C and 750 °C
- Battery positive voltage between 10 V and 16 V
- All 4 oxygen sensors ready for operation
- Travel, partially loaded, for approx. 20 minutes

Possible fault cause
- Electrical fault in the inlet camshaft adjustment device
- Leaking exhaust system
- Oxygen sensor ahead of catalytic converter faulty
- Mechanical fault in valve drive

Diagnosis/troubleshooting
- Do not use contact spray on the oxygen sensor plug connections, as this may cause irreparable damage to the wiring (blocking the reference air channels).
- Do not confuse oxygen sensor ahead of catalytic converter and oxygen sensor after catalytic converter as this will cause implausible fault entries.

Distinguishing feature of both sensors:







Oxygen sensor ahead of catalytic converter (LSU) has a 6-pole connector







Oxygen sensor after catalytic converter (LSF) has a 4-pole connector