Barometric Pressure Sensor Circuit Low
The P2228 code indicates that the Engine Control Module (ECM) has detected a voltage signal from the barometric pressure (BARO) sensor that is lower than the expected range. This sensor measures atmospheric pressure to help the ECM adjust fuel delivery and ignition timing. A low circuit condition typically means the signal voltage is near zero, often due to a short to ground, open circuit, or a faulty sensor. This can lead to incorrect air-fuel mixture, affecting engine performance and emissions.
01. Most Common Causes
- Faulty barometric pressure sensor
- Short to ground in the sensor signal circuit
- Open or damaged wiring/connectors
- Corroded or loose electrical connections
- Failed ECM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor engine performance (hesitation, rough idle)
- Decreased fuel economy
- Hard starting or stalling
- Failed emissions test
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the BARO sensor and its wiring for damage, corrosion, or loose connections.
Step 3: With the ignition on, measure the signal voltage at the sensor connector (should be around 4.5-5V with engine off). If low, check for shorts or opens.
Step 4: Compare BARO sensor reading with a known good sensor or use a scan tool to view live data; replace sensor if faulty.
Step 5: If wiring and sensor are okay, test the ECM's reference voltage and ground circuits; if all pass, consider ECM replacement.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally not recommended to drive long distances as the engine may run poorly, potentially causing further damage or leaving you stranded. Short trips to a repair shop are usually okay.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150, including parts (sensor $30-$80) and labor ($20-$70). Diagnostic fees may apply.