P2238 code meaning
O2 Sensor Positive Current Control Circuit Low (Bank 1 Sensor 1)
Powertrain system Generic code P22xx codes Check engine light
What P2238 means
P2238 is the low-side fault of the pump-current circuit of the front wide-band sensor on bank 1. Saab's 9-5 2.0 turbo (2010) shows a concrete test: on deceleration with the injectors shut off, pure air should drive the signal well above its stoichiometric level, and if it stays below 1.7 V for 3 s the code sets as Type B. GM's 2005 V6 tables use the same fuel-cut check but book it under P2237. Mitsubishi's 2022 Outlander lists P2238 as a two-trip code. Ford does not use it at all: a pump-current wire shorted to ground lands in P0131 there. P2237 is the open circuit, P2239 the high-side fault, P2241 the same on bank 2. Typical findings are a grounded IP wire or a sensor that can no longer pump oxygen.
P2238 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 P2238
- Check engine light after two drives
- Lambda value does not rise during coasting in live data
Common causes of P2238
- Most likelyPump-current wire chafed through to ground
- PossibleAged or contaminated sensor that no longer reads lean in fuel cut-off
- Less likelyFault in the sensor interface of 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 P2238 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). |
| 38 | The exact fault in that area. |
What to do next
- Note P2238 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 P2238
What does P2238 mean?
P2238 means "O2 Sensor Positive Current Control Circuit Low (Bank 1 Sensor 1)". P2238 is the low-side fault of the pump-current circuit of the front wide-band sensor on bank 1. It is a generic code, so it means the same on every make.
Is it safe to drive with P2238?
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 P2238 fail an emissions test?
Yes, it can. P2238 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 P2238 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 P2238 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.