Faulty barometric pressure sensor B, including internal failure or contamination.; Damaged or corroded wiring or connector at the sensor or PCM, causing an intermittent or out-of-range signal.; A restricted or blocked pressure port or hose connected to the sensor, leading to inaccurate readings.; PCM software issue or internal fault in the sensor signal processing circuit.; Poor electrical ground connection for the sensor circuit, causing voltage reference errors.; Aftermarket modifications or incorrect sensor replacement that does not meet OEM specifications.

DTC codes / P22xx · Fuel and air metering (injector circuits) / P222B

P222BBarometric Pressure Sensor B Circuit Range/Performance

Q: What does code P222B mean?

Barometric Pressure Sensor B Circuit Range/Performance. P222B indicates that the powertrain control module (PCM) has detected an out-of-range or performance fault in the Barometric Pressure Sensor B circuit, which is often a secondary barometric pressure sensor used for altitude compensation. The PCM compares the sensor's signal against expected values under specific operating conditions and sets the code when the signal falls outside the allowable range or fails a rationality check.

P222B indicates that the powertrain control module (PCM) has detected an out-of-range or performance fault in the Barometric Pressure Sensor B circuit, which is often a secondary barometric pressure sensor used for altitude compensation. The PCM compares the sensor's signal against expected values under specific operating conditions and sets the code when the signal falls outside the allowable range or fails a rationality check.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the malfunction indicator lamp (MIL) on the dashboard, often with no other noticeable symptoms.
Rough idle or poor engine performance, especially at high altitudes where barometric pressure readings are critical.
Reduced fuel economy or improper air-fuel ratio control, leading to occasional hesitation or stumble.
In some vehicles, the engine may enter limp mode or limit power to protect the engine.
A stored code may be accompanied by other sensor codes, such as mass air flow (MAF) or manifold absolute pressure (MAP) sensor codes.

Common causes, most likely first

Faulty barometric pressure sensor B, including internal failure or contamination.
Damaged or corroded wiring or connector at the sensor or PCM, causing an intermittent or out-of-range signal.
A restricted or blocked pressure port or hose connected to the sensor, leading to inaccurate readings.
PCM software issue or internal fault in the sensor signal processing circuit.
Poor electrical ground connection for the sensor circuit, causing voltage reference errors.
Aftermarket modifications or incorrect sensor replacement that does not meet OEM specifications.

How to diagnose and fix it

Use an OBD-II scanner to retrieve the code and check for any related pending or stored codes; clear the code and test-drive to see if it returns.
Visually inspect the barometric pressure sensor B and its wiring harness for damage, corrosion, or loose connections; repair as needed.
Check the sensor's pressure port and hose for blockage or leaks; clean or replace if restricted.
Measure the sensor's reference voltage and signal voltage with a digital multimeter (DMM) and compare to manufacturer specifications; replace the sensor if readings are out of range.
Perform a wiggle test on the wiring while monitoring sensor data to identify intermittent faults; repair wiring as necessary.
If the sensor and wiring are good, check for PCM software updates or known issues; reprogram or replace the PCM only as a last resort.
After repairs, clear codes and verify the fix by completing a drive cycle that includes the conditions needed for the barometric pressure rationality test.

Barometric Sensor B Faults You Might Overlook

Many vehicles use multiple barometric pressure sensors, and Sensor B is often a secondary sensor integrated into the mass air flow (MAF) sensor or a separate unit; misidentifying the correct sensor leads to unnecessary replacements.
A dirty or contaminated sensor port can cause this code without any electrical fault, so always check for debris or oil buildup before condemning the sensor.
The PCM may set P222B due to a faulty ground connection shared with other sensors, so a voltage drop test on the ground circuit is a crucial step that is often skipped.
In some cases, a weak battery or charging system issue can cause voltage spikes that trigger this code, so check the charging system before replacing parts.
P222B can be set by a performance issue rather than a complete failure, meaning the sensor may still produce a signal but not within the expected range under certain conditions, such as during altitude changes.

Can I keep driving with P222B?

The vehicle is generally safe to drive with P222B, but you may experience reduced performance or fuel economy, especially at high altitudes. Avoid sustained heavy loads or towing until the fault is diagnosed, and have the vehicle inspected promptly to prevent potential drivability issues.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.