What it means
The barometric (ambient) pressure sensor reports a voltage below the valid window. The ECU uses this signal to compensate fuel and boost calculations for altitude — a stuck-low value tricks the ECU into thinking the car is at high altitude.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Barometric Pressure Sensor A measures ambient pressure, which the engine control module uses for altitude-related air and boost calculations. P2228 sets when Sensor A's signal falls below the valid range, so the module may interpret the pressure as unusually low.
Common causes
Most likely first.
- Barometric pressure sensor failed
- Signal shorted to ground
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light on
- Reduced engine performance
- Increased fuel consumption
- Hesitation or rough running
How to diagnose it
- Record freeze-frame data and compare Sensor A's pressure reading with local conditions and other available pressure readings.
- Inspect Sensor A's connector and harness for corrosion, loose pins, or a signal wire rubbed through against ground.
- Using the vehicle wiring information, check the Sensor A signal circuit for a short to ground and inspect its power and ground connections.
- Check terminal fit and circuit continuity, then compare the sensor signal with the manufacturer's specification.
- If the wiring and connections pass, test Barometric Pressure Sensor A using the manufacturer's diagnostic procedure.
Common fixes
- Clean and secure corroded or loose Sensor A connector pins.
- Repair a signal wire shorted to ground or otherwise damaged.
- Restore a poor Sensor A power or ground connection.
- Replace Barometric Pressure Sensor A if it continues to report below range with a verified circuit.
Can I keep driving?
Cautious driving is generally possible if the engine runs normally, but low pressure input may cause hesitation, reduced performance, or higher fuel use. Avoid hard acceleration if the vehicle responds poorly and have the circuit checked soon.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.