P223FO2 Sensor Reference Resistance Out Of Range (Bank 2)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P223F is the reference-cell resistance check for the front wide-band sensor of bank 2. GM's 2016 and 2018 tables translate the measured resistance into element temperature and count readings below 700 °C or above 1,000 °C; 64 of 80 samples (2018) or 128 of 160 (2016) at 25 ms set a Type B code. The monitor waits for heater warm-up plus 20 s and is blocked while the bank 2 heater codes P0050-P0052 or P0155 are present, so a pure heater fault shows up there first. A reading that is too cold despite a working heater points to a sensor whose ceramic has aged and become high-resistance; too hot suggests overheating, for example from misfire. Bosch's LSU 4.9 data sheet gives 300 ohms as the nominal cell resistance. P223E is bank 1, P223D the pump-current check of the same sensor.
- What you may notice
- Check engine light after two drives
- Bank 2 lambda control slow to become active after a cold start
- Likely causes
- LikelyBank 2 sensor ceramic aged and high-resistance
- PossibleWeak heater supply or high resistance in the heater wiring
- RareSensor overheated by misfire or very high exhaust temperature
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €90 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.