Operation CHARM: Car repair manuals for everyone.

P0139







P0139
Aging of Oxygen Sensor after Three Way Catalytic Converter (TWC) (cylinders 1 - 3)

P0159
Aging of Oxygen Sensor after Three Way Catalytic Converter (TWC) (cylinders 4 - 6)

Function
The oxygen sensors after the catalytic converter serve the purpose of pilot control of the oxygen sensors ahead of the catalytic converter. This allows correction of any oxygen sensor characteristic displacement ahead of the catalytic converter.

Diagnosis conditions
- Engine speed between 1400 1/min and 3000 1/min.
- Engine load between 0.9 ms and 2.6 ms.
- Oxygen sensor heating active.
- Oxygen sensing ahead of catalytic converter active.
- Calculated catalytic converter temperature > 300°C.
- No secondary air injection.
- No faults detected for fuel tank ventilation and secondary air injection.





Diagnostic procedure
Road test vehicle
1. Erase DTC memory.
2. Heat oxygen sensors (road test vehicle under load, run engine under no load at high engine speed).
3. Road test vehicle, whereby the diagnosis conditions must be reached.

NOTE: Diagnosis has been performed if cycle flag No. 2 is set.

4. Read DTC memory.