P2239O2 Sensor Positive Current Control Circuit High (Bank 1 Sensor 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2239 is the high-side counterpart for the pump-current circuit of the bank 1 front wide-band sensor. On the Saab 9-5 2.0 turbo (2010) it sets when, in closed loop with the mixture deliberately enriched, the signal still sits at 1.48-1.51 V for 1 s, meaning the sensor ignores a change it should report; it is a Type B code. GM's 2005 V6 tables check a similar window (1.48-1.52 V while target lambda lies outside 0.97-1.03) under P2237. Mitsubishi's 2022 Outlander also lists P2239 as a two-trip code. Ford files this wire touching battery voltage under P0132 instead. A short to the heater supply can overload the sensor interface, so the wiring deserves a check before a new sensor goes in. P2238 is low, P2242 bank 2.
- What you may notice
- Check engine light after two drives
- Lambda reading frozen near 1.0 regardless of load
- New sensor fails again quickly if the wiring short is not found
- Likely causes
- LikelyPump-current wire shorted to heater supply or battery voltage
- PossibleWide-band sensor with internal short or stuck output
- RareDamaged sensor interface in the ECM
- 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: €80 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.