Ageing of Oxygen Sensor After TWC
P0139
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