Powertrain, generic (extended)

P223F O2 Sensor Reference Resistance Out Of Range (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

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.

Likely causes

Bank 2 sensor ceramic aged and high-resistance
Weak heater supply or high resistance in the heater wiring
Sensor overheated by misfire or very high exhaust temperature

Symptoms

  • Check engine light after two drives
  • Bank 2 lambda control slow to become active after a cold start

Repair estimate

DifficultyMediumDIY possible
Parts and labour€90–450
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

oxygen sensor bank2 sensor1oxygen sensor heaterecm

Related codes

P223EP223DP0050P0155

References: gsi.ext.gm.com, gsi.ext.gm.com, bosch-motorsport.com, law.cornell.edu.