Kazalo kodova grešaka · medium
P0138
HO2 Sensor sense circuit high voltage – bank 1, downstream (1/2)
HO2 Sensor sense circuit high voltage – 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 sensing circuit: short circuit to high voltage HO2 Sensor 1/2 ground (BRD – braided shield) open circuit 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)