P222F: Barometric Pressure Sensor A/B Correlation

What it means

Barometric pressure sensors A and B disagree by more than the allowed tolerance. Used for redundancy on hybrid and emission-critical systems.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

Barometric Pressure Sensors A and B provide ambient pressure readings that the controller can compare for plausibility. P222F sets when their readings differ beyond the allowed tolerance, pointing to a drifting sensor, a circuit fault, or a restricted pressure port if the vehicle has one.

Common causes

Most likely first.

1. One barometric pressure sensor drifting or failing
2. Damaged wiring or poor connector contact
3. Blocked or damaged sensor pressure port, if fitted
4. Fault in the sensor reference or ground circuit

Symptoms

• Check-engine light on
• Reduced engine performance
• Increased fuel consumption
• Hesitation or rough running

How to diagnose it

1. Record freeze-frame data and compare live readings from Sensors A and B with each other and with plausible local barometric pressure.
2. Check whether the readings change consistently with engine operating conditions and ambient pressure, using the vehicle's service information to interpret the data.
3. Inspect both sensor connectors and harnesses for corrosion, moisture, damaged terminals, chafing, or loose grounds.
4. Check each sensor's reference, ground, and signal circuits for opens, shorts, or poor connections.
5. Inspect each sensor's pressure port if fitted, then test the sensors against the manufacturer's specification to identify which reading is inaccurate.

Common fixes

• Clean and secure a poor connection at the affected sensor.
• Repair damaged wiring or ground connections in the affected sensor circuit.
• Clear debris from a blocked pressure port if fitted and serviceable.
• Replace the sensor shown by testing to be drifting or inaccurate.

Can I keep driving?

A short trip may be reasonable if the engine runs normally, but avoid heavy loads if performance is reduced. The controller may calculate fueling or load incorrectly, worsening fuel economy and emissions.