P223EO2 Sensor Reference Resistance Out Of Range (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P223E checks the internal resistance of the reference (Nernst) cell in the bank 1 wide-band sensor. That resistance falls as the ceramic heats up, so the ECM uses it as a thermometer; Bosch specifies 300 ohms nominal for the LSU 4.9 at operating temperature. GM's tables (2016-2019) convert the value supplied by the interface chip into an element temperature and flag anything below 700 °C or above 1,000 °C in 80 % of samples (64 of 80 in 2018, 128 of 160 in 2016/2019), starting 20 s after heater warm-up; the code is Type B. GM bulletin 16-NA-266 covers 2016-2017 ATS, CTS, CT6, Camaro, Malibu and Envision with the 2.0 turbo LTG: a voltage spike inside the ECM sets P223E or P0132 and also blocks remote start, cured by reprogramming. P223F is bank 2, P0135 the heater itself.
- What you may notice
- Check engine light after two consecutive drives
- Remote start refuses to start the engine (GM LTG models)
- Likely causes
- LikelyAged sensor whose reference cell resistance has drifted
- PossibleHeater not holding the element at temperature (heater, wiring or control)
- PossibleECM calibration fault on GM 2.0 turbo LTG (bulletin 16-NA-266)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.