Barometric Pressure Sensor A Circuit High
What it means
P2229 means the ECM sees a higher-than-expected voltage on the barometric pressure sensor "A" signal circuit — usually an open or a short to voltage in the wiring, or a failed sensor. The barometric sensor (often built into the MAP sensor) tells the ECM the ambient air pressure so it can compensate for altitude. The car drives normally, with the main effect being slightly less accurate fueling, especially at high elevation.
Can I keep driving? Safe to drive — a barometric pressure signal fault mainly affects altitude compensation, so you may notice slightly reduced performance or economy, especially at high altitude.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable driving symptom
- Minor hesitation or reduced performance, most likely at altitude
- Slight drop in fuel economy
Common causes
Most likely first
- Faulty barometric pressure sensor (often integrated into the MAP sensor)Likely
- Open circuit or short to voltage in the sensor signal wiring (high reading)Common
- Poor electrical connection or corrosion at the sensor connectorCommon
- Faulty ECM (least likely)Less often
How to diagnose & fix
Work through it in order
- Do a careful visual inspection of the sensor and its connector for damage, corrosion, or loose pins.
- With the key on and engine off, check for a steady 5-volt reference and a good ground at the sensor.
- Compare the sensor's barometric reading on a scan tool to the actual pressure for your altitude — a fixed high value points to an open signal or the sensor.
- Repair the wiring or replace the barometric/MAP pressure sensor, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2229?+
Can I just clear P2229?+
Related codes
Often seen with P2229
Read & clear P2229 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.