P2239 code meaning
O2 Sensor Positive Current Control Circuit High (Bank 1 Sensor 1)
Powertrain system Generic code P22xx codes Check engine light
What P2239 means
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.
P2239 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P2239
- 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
Common causes of P2239
- Most likelyPump-current wire shorted to heater supply or battery voltage
- PossibleWide-band sensor with internal short or stuck output
- Less likelyDamaged sensor interface in the ECM
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 wiringECM
What each part of P2239 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). |
| 39 | The exact fault in that area. |
What to do next
- Note P2239 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 P2239
What does P2239 mean?
P2239 means "O2 Sensor Positive Current Control Circuit High (Bank 1 Sensor 1)". P2239 is the high-side counterpart for the pump-current circuit of the bank 1 front wide-band sensor. It is a generic code, so it means the same on every make.
Is it safe to drive with P2239?
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 P2239 fail an emissions test?
Yes, it can. P2239 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 P2239 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2239 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.