Diagnostic article Generic OBD-II
P27D2: Valve-five stuck-on uses a larger single-rod movement criterion
P27D2 evaluates unintended rod-five travel shortly after a selector change, with a source narrative limitation noted explicitly.
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Documented application
2025 GM 25OBDG07A Part 2 documented monitor only; its application-matrix filename join is unresolved. No model, engine or universal calibration applicability is inferred.
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.
The P27D2 criteria concern synchronizer actuation valve five and rod five. They list unintended rod displacement of at least 4,000 micrometres within 200 ms of a selector-target change, while rod-five force target is zero. This differs from the paired-rod movement and relaxation criteria used for other valves in the same file.
Use the actual criteria, not a copied pattern
Both hydraulic-on and hydraulic-off selector targets appear as alternative cases. The source requires no electrical fault for rod-five position or valve five and excludes application error and bypass states. The movement must therefore occur without an intended rod-force request in a valid diagnostic state.
The narrative still discusses relaxation of another rod, but the explicit P27D2 criteria name only rod five. That inconsistency remains flagged; this article does not invent a second rod or apply another valve’s 125-micrometre relaxation test.
Verification focus
Preserve selector timing, rod-five position and its zero-force command together. A later stationary position cannot show the unintended transition. Applicable service information must resolve the exact implementation before intrusive operation. The monitor’s hydraulic classification does not alone identify the specific failed internal part.
Document scope and source
2025 GM 25OBDG07A Part 2 documented monitor only; its application-matrix filename join is unresolved. No model, engine or universal calibration applicability is inferred. These figures explain the cited controller logic, not a vehicle-specific repair instruction. Match the vehicle’s service information before applying them.
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
Pressure Control Solenoid S Stuck On
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