P2A38 code meaning
O2 Sensor Positive Current Control Circuit/Open Bank 1 Sensor 3
Powertrain system Generic code P2Axx codes Check engine light
What P2A38 means
P2A38 reports that the lead carrying positive current control for bank 1's third oxygen sensor has no continuity. That sensor sits behind a second converter or a later aftertreatment stage, and the code only makes sense where this position carries a wide-band probe: through this lead (pin APE/IP on a Bosch LSU 4.9) the controller drives between about −2 and +2.25 mA into the pump cell. No manufacturer documents P2A38 publicly. For the upstream twin P2237, Ford's 2012 summary spots a broken IP wire because lambda barely moves during deliberate reference-current pulses; its own third sensors are switching types with heater codes only. P2A39/P2A3A are the low/high faults, P2A3B the open return. The lamp lights, while driving feels unchanged.
P2A38 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2A38
- Check engine light
- Sensor 3 value frozen near lambda 1 in live data
- Downstream emission monitors not completed
Common causes of P2A38
- Most likelyBroken pump-current wire or pushed-back pin in the sensor plug
- PossibleSensor plug loose or not latched after exhaust work
- Less likelyInternal break in the pump cell of the probe
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor b1s3Wiring harnessECM
What each part of P2A38 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| A | Area: hybrid propulsion. |
| 38 | The exact fault in that area. |
What to do next
- Note P2A38 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 P2A38
What does P2A38 mean?
P2A38 means "O2 Sensor Positive Current Control Circuit/Open Bank 1 Sensor 3". P2A38 reports that the lead carrying positive current control for bank 1's third oxygen sensor has no continuity. It is a generic code, so it means the same on every make.
Is it safe to drive with P2A38?
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 P2A38 fail an emissions test?
Yes, it can. P2A38 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 P2A38 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2A38 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.