Diagnostic article Generic OBD-II
P222B: Separating physical pressure range faults from sensor cross-check failures
Understand the multiple documented paths to P222B and why a raw voltage reading alone cannot identify the failed comparison.
Read before applying this article
Documented application
2025 GM 25OBDG07A Part 2 monitor tables only; model, engine and transmission applicability are not established by the unresolved application-matrix filename join.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P222B is the range/performance diagnosis for auxiliary barometric-pressure sensor B in the generic catalog. The documented GM implementation identifies bank 2 and groups several plausibility checks under this code, rather than assigning one fixed electrical limit.
Four reported categories share the code
The source lists physical-range high and low faults, plus high and low sensor cross-check faults. The first pair concerns whether the pressure is physically plausible; the second concerns agreement with comparison information. A code readout alone does not reveal which category triggered.
All four rows require ignition on and refer to separate inhibition tables. The summary presents detected-fault status for these checks but does not publish a complete numeric pressure boundary or the full cross-check calculation on these pages.
Preserve the distinction during diagnosis
An in-range raw electrical or digital signal does not establish that the pressure value is plausible. Equally, a cross-check failure does not uniquely prove that this sensor, rather than its comparison information, is wrong. Those are different questions from the raw digital limits listed for P222C and P222D.
Useful evidence includes the available subtest status, the pressure value and the relevant comparison signals with their validity. If the tool cannot identify the failed branch, the applicable workshop information is needed before selecting a test threshold. Inventing one universal pressure difference from this summary would exceed the evidence. The source supports a plausibility investigation, not an automatic sensor replacement.
Source and scope
2025 GM 25OBDG07A Part 2 monitor tables only; model, engine and transmission applicability are not established by the unresolved application-matrix filename join. These are documented monitor criteria, not a universal repair procedure. GM PDF, physical page 878 · GM PDF, physical page 879 · GM PDF, physical page 880.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Barometric Pressure Sensor B Circuit Range/Performance
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT