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 720 rpm and 2400 rpm.
Engine load between 0.8 ms and 2.6 ms.
Oxygen sensor heating active.
Oxygen sensing ahead of catalytic converter active.
Calculated catalytic converter temperature > 352°C.
No secondary air injection.
No fuel tank ventilation.
No faults detected for fuel tank ventilation and secondary air injection.

Wiring Diagram:




Diagnostic Procedure:



1. Road test vehicle or perform short test.
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 or perform short test, whereby the diagnosis conditions must be reached.
4. Read DTC memory.