Diagnostic article Generic OBD-II
P2272: A lean-biased rear-sensor code with an unresolved bank label in the source
Understand the documented rich-response principle behind P2272 while keeping the source’s bank designation limitation explicit.
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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.
P2272 is generically bank 2 sensor 2 biased or stuck lean. The cited GM row carries P2272 but repeatedly names bank 1 in its strategy and conditions. Visual inspection confirms that wording in the original PDF. This article does not silently convert those references into a physical bank 2 test procedure.
The row describes an intrusive response check
The stated strategy commands a rich mixture and evaluates whether the secondary oxygen-sensor maximum voltage rises sufficiently. The printed failure boundary is below 0.8 V during that rich shift. That is a documented response criterion, not a universal steady-idle voltage limit.
The continuation qualifies the check with exhaust-flow stability, accumulated gas mass, sensor readiness and modeled catalyst-temperature conditions. A rear sensor observed before the commanded mixture has reached it cannot be judged as though that response test were complete.
What can be concluded despite the bank ambiguity
The useful principle is to distinguish failure to respond to a verified rich command from a merely low voltage seen without controlled conditions. The code alone does not identify an electrically failed sensor or prove a particular mixture cause.
The exact vehicle and calibration information must resolve the bank-specific application before the printed thresholds are used for diagnosis. Preserve command, upstream confirmation, rear response and monitor eligibility. The source limitation prevents a confident component-location instruction or replacement decision from this table alone, while the documented response logic remains useful for understanding the type of evidence required.
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 490 · GM PDF, physical page 491 · GM PDF, physical page 492.
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
O2 Sensor Signal Biased/Stuck Lean Bank 2 Sensor 2
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