Barometric Pressure Sensor A Circuit Low
The P2228 code means the vehicle's onboard diagnostic system has detected: Barometric Pressure Sensor A Circuit Low. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $40 - $250 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Lean running condition
- Decreased performance at lower altitudes
- Poor fuel economy
- Slight hesitation on acceleration
Probable Causes (Ranked by Likelihood)
- Open circuit in the BARO sensor A wiring Very High
- Failed barometric pressure sensor A High
- Corroded sensor A connector Moderate
- Sensor reference voltage supply issue Moderate
- ECM internal fault on sensor A input Low
Frequently Asked Questions
What is the difference between BARO sensor A and B?
Some vehicles use dual barometric pressure sensors (A and B) for redundancy or for different measurement ranges. Sensor A and B codes refer to specific sensor circuits within the system.
What voltage should the BARO sensor reference be?
Most BARO sensors use a 5V reference voltage from the ECM. If this reference is missing or low, the sensor cannot produce an accurate reading.
Can a low BARO reading cause the engine to run lean?
Yes, a low barometric pressure reading tells the ECM the vehicle is at a higher altitude than it actually is, causing it to reduce fuel delivery and potentially creating a lean running condition.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Read BARO sensor A value with a scan tool and compare to actual atmospheric pressure
-
Check for 5V reference voltage at the sensor connector
-
Inspect wiring from sensor A to the ECM for open circuits
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Test the sensor ground circuit for continuity
-
Replace the sensor if wiring and voltage supply are confirmed good
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
P2228 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
Commonly Affected Vehicles
- 2010-2020 Toyota Tacoma
- 2012-2020 Honda CR-V
- 2011-2019 Ford Explorer
- 2013-2020 Hyundai Elantra
- 2009-2018 Nissan Frontier
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