Diagnostic article Generic OBD-II
P222D: Understanding a high digital reading from barometric sensor B
See why P222D’s raw-count threshold must be kept separate from measured pressure and sensor cross-check results.
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.
P222D evaluates the upper raw-data limit of the bank 2 barometric-pressure sensor in the cited GM calibration. The monitor's numerical boundary is expressed in digital counts. A generic scanner description of “circuit high” does not change those counts into volts or a real atmospheric-pressure measurement.
The upper end of the data range
The source sets the criterion at a raw value of 4,088 or greater and lists a fifty-millisecond evaluation period. Ignition must be on, the specified HFM chip heating/standby status must be false, and additional inhibition rules apply.
A converted pressure shown after a raw-data range failure may not be independently meaningful. The useful first question is whether the input itself was valid, rather than whether the vehicle was operating at a particular altitude.
Different pressure checks answer different questions
Adjacent rows separately describe sensor self-diagnosis and P222B physical-range or cross-check faults. A high digital range result is not interchangeable with those categories. Identifying the exact diagnostic path prevents a generic “pressure sensor bad” conclusion from discarding useful evidence.
Retain raw data if available, operating status and the fault sequence. The vehicle-specific sensor and communication information is needed to isolate why the reported data reached the invalid range. This summary does not establish an external voltage probing method, a component location or proof that replacing the sensor will resolve every P222D occurrence.
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 High
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