Barometric Pressure Sensor Circuit Low
The P222C 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 sensor's output voltage is too low, often due to a short to ground, faulty sensor, or wiring issues. This can lead to incorrect air-fuel mixture calculations, affecting engine performance.
01. Most Common Causes
- Faulty barometric pressure sensor
- Short to ground in sensor circuit
- Open or damaged wiring/connector
- Corroded or loose electrical connections
- Failed ECM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor engine performance or hesitation
- Reduced fuel economy
- Rough idle or stalling
- Hard starting
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: Test the sensor's voltage reference and ground at the connector using a multimeter.
Step 4: Compare the sensor output voltage to manufacturer specifications; replace if out of range.
Step 5: If wiring and sensor are good, test the ECM's ability to read the signal; consider ECM replacement as last resort.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the incorrect air-fuel mixture can cause poor performance, increased emissions, and potential damage to the catalytic converter.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150, including parts (sensor $30-$80) and labor ($20-$70). Diagnosis fees may apply.