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
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References
sae:J2012