What it means
Barometric sensor B reads in range but plausibility check fails — slow response or stuck reading. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Barometric Pressure Sensor B is a secondary or redundant sensor used to report atmospheric pressure for altitude compensation. P222B sets when its signal remains electrically in range but fails a plausibility check, such as being stuck or responding too slowly compared with expected pressure conditions.
Common causes
Most likely first.
- Sensor drift
- Sensor element aged beyond calibration window
- Sensor mounting loose - signal damping
Symptoms
- Check-engine light on
- Reduced engine performance
- Increased fuel consumption
- Hesitation or rough running
How to diagnose it
- Save freeze-frame data and compare Sensor B's reading with local atmospheric pressure, Sensor A, and other available pressure readings.
- Watch Sensor B live data under the operating conditions specified by the manufacturer to see whether it changes plausibly or remains stuck.
- Inspect Sensor B's mounting, connector seal, terminals, and harness for looseness, water ingress, corrosion, or pin push-back.
- With live data displayed, gently move the Sensor B harness and connector to check for signal changes or dropouts.
- If the connections and mounting are sound, test Sensor B for drift or slow response against the manufacturer's specification.
Common fixes
- Secure a loose Sensor B mounting that is damping or disturbing its reading.
- Dry and clean connector terminals and restore a sound connector seal where needed.
- Repair damaged wiring or terminals that cause a sluggish or unstable signal.
- Replace Barometric Pressure Sensor B if it remains stuck or responds outside the manufacturer's limits.
Can I keep driving?
If the engine runs normally, cautious driving is generally possible, but reduced performance, hesitation, or increased fuel use may continue. Avoid hard acceleration if response is inconsistent and have the secondary pressure reading checked.
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.