P223E code meaning
O2 Sensor Reference Resistance Out Of Range (Bank 1)
Powertrain system Generic code P22xx codes Check engine light
What P223E means
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.
P223E at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.3 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P223E
- Check engine light after two consecutive drives
- Remote start refuses to start the engine (GM LTG models)
Common causes of P223E
- Most 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)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor bank1 sensor1Oxygen sensor heaterECM
What each part of P223E means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 2 | Area: fuel and air metering (injector circuit). |
| 3E | The exact fault in that area. |
What to do next
- Note P223E and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P223E
What does P223E mean?
P223E means "O2 Sensor Reference Resistance Out Of Range (Bank 1)". P223E checks the internal resistance of the reference (Nernst) cell in the bank 1 wide-band sensor. It is a generic code, so it means the same on every make.
Is it safe to drive with P223E?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P223E fail an emissions test?
Yes, it can. P223E is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P223E to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. This is a job for a workshop.
Will P223E clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.