Powertrain
generic / SAE
P0139
O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
The ECU detects that the downstream oxygen sensor on bank 1 reports an abnormally high voltage signal, suggesting a persistently rich exhaust condition past the catalyst, a shorted sensor, or wiring shorted to a voltage source.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 39
Possible causes
- Engine running rich (leaking injector, high fuel pressure) high
- Sensor signal wire shorted to voltage medium
- Downstream O2 sensor failed medium
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Inspection / repair
- Difficulty: easy
- DIY: possible
- Estimated cost: 80–350 €
- Estimated time: 0.3–1.5 h
- Component: oxygen sensor b1s2
- Component: oxygen sensor wiring
- Component: catalytic converter bank1
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012