17 Ageing of Oxygen Sensor After TWC, Bank 1

P0139

17 Ageing of Oxygen Sensor After TWC, Bank 1

Function
The diagnosis function is responsible for checking the voltage position of the sensor after the catalytic converter. This happens in 2 areas:
1. After 5 seconds of the deceleration phase, the sensor voltage must be less than 0.1 V.
2. If the sensor voltage remains above or below 0.6 V for longer than 80 seconds, the mixture is made lean or enriched -> the voltage must change.

Diagnosis conditions
- Air flow rate from 25 to 120 kg/h
- Oxygen sensing after TWC is active
- Basic adaptation has reached steady condition
- No secondary air diagnosis
- No fuel tank ventilation diagnosis
- EVAP canister not highly loaded
- No fault in EVAP canister purge valve, fuel tank ventilation system, secondary air injection, oxygen sensor heating after TWC, rpm/crankshaft position sensor and fuel supply system

P0139 - P0159:

Wiring Diagram







Diagnosis Procedure







1 Road test vehicle or perform short test.
1. Erase the fault memory.
2. Heat the oxygen sensors (road test car under load, run engine without load at high rpm).
3. Road test vehicle or perform short test, ensuring that the diagnosis conditions are reached.
4. Read out the fault memory.