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 signal voltage is near zero, often due to a short to ground, open circuit, or a faulty sensor. This can cause incorrect air-fuel mixture calculations, leading to performance issues.
1. Most Common Causes
- Faulty barometric pressure sensor
- Short to ground in sensor signal circuit
- Open circuit in sensor signal or reference voltage
- Corroded or damaged wiring/connectors
- Failed ECM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor engine performance or hesitation
- Rough idle or stalling
- Decreased fuel economy
- Failed emissions test
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Visually inspect the BARO sensor and wiring for damage, corrosion, or loose connections.
Step 3: Using a multimeter, check the sensor's reference voltage (typically 5V) and ground at the connector.
Step 4: Measure the signal voltage from the sensor with ignition on; compare to expected values (usually 2.5-4.5V at sea level).
Step 5: If signal voltage is low, disconnect sensor and check for short to ground in the signal wire; repair as needed.
Step 6: If wiring is okay, replace the barometric pressure sensor.
4. 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, stall, or have reduced power. However, you can drive short distances to a repair shop if necessary.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150, including parts and labor. The sensor itself is often inexpensive ($20-$50), and labor is usually under an hour.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.