Fejlkodeindeks · medium
P0140
HO2 Sensor sense circuit no activity – bank 1, downstream (1/2)
HO2 Sensor sense circuit no activity – bank 1, downstream (1/2)
Documented for: 2.0L gasoline; 2.5L/3.0L gasoline · System(s): EMS EOBD, EMS OBD II · Factory MIL flag: 2
Common causes
- HO2 Sensor 1/2 disconnected HO2 Sensor 1/2 mechanical damage HO2 Sensor 1/2 to ECM wiring open circuit HO2 Sensor 1/2 sensing circuit short circuit to high voltage HO2 Sensor 1/2 short circuit to ground HO2 Sensor 1/2 ground (BRD – braided shield) open circuit Exhaust leak Low exhaust temperature HO2 Sensor 1/2 failure
- HO2 Sensor 1/2 disconnected HO2 Sensor 1/2 mechanical damage HO2 Sensor 1/2 to ECM wiring open circuit HO2 Sensor 1/2 sensing circuit: short circuit to high voltage HO2 Sensor 1/2 short circuit to ground HO2 Sensor 1/2 ground (BRD – braided shield) open circuit Exhaust leak Low exhaust temperature HO2 Sensor 1/2 failure
Quick checks
- Confirm freeze-frame and conditions when the code set
- Inspect connectors, grounds, and harness for the circuit named in the code
- Compare live sensor values vs expected (unplugged/biased sensors are common)
- Check intake boots, PCV, and vacuum lines for splits (very common on aged X-Types)