P2228
Barometric Pressure Sensor A Circuit Low
Fuel & air metering (barometric pressure)
Generic OBD-II
Medium
What it means
P2228 means the barometric pressure sensor signal is reading abnormally low — the circuit voltage is below the expected range. This sensor (often built into the MAP sensor) tells the ECM the local atmospheric pressure so it can trim fueling for altitude. The car usually still runs on a default value, but performance and economy can suffer until the sensor or wiring is fixed.
Medium
Can I keep driving? Usually drivable — the ECM falls back to a default reading, though you may notice slightly rough running or reduced performance, especially at altitude or under load.
Common symptoms
What you'll notice
- Check-engine light on
- Often no obvious driving symptoms
- Slightly rough running or hesitation
- Reduced performance or economy, especially at altitude
Common causes
Most likely first
- Faulty barometric/MAP pressure sensor reading lowLikely
- Short-to-ground or open in the sensor signal wiringCommon
- Poor or corroded connection at the sensorCommon
- Faulty ECM/PCMLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame and view the barometric pressure value; a stuck-low reading confirms the fault.
- Do a careful visual inspection of the sensor and its connector for corrosion or damage.
- Check the signal wire for a short to ground and confirm the 5-volt reference and ground are present.
- Compare the barometric reading against known atmospheric pressure for your altitude.
- If reference, ground, and wiring are good, replace the barometric/MAP pressure sensor and retest.
FAQ
Quick answers
Is it safe to drive with P2228?+
Generally yes. The ECM uses a substitute barometric value, so the car runs, but fueling accuracy suffers, so repair it before it affects economy or emissions.
Can I just clear P2228?+
It returns until the sensor or its low-reading circuit is repaired, since the ECM continuously checks the barometric signal.
Related codes
Often seen with P2228
Read & clear P2228 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX