Diagnostic article Generic OBD-II
P27D1: Valve five needs current-profile evidence because no alternate path exists
P27D1 distinguishes a stuck valve-five path from frozen rod-five feedback using repeated current-profile results.
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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.
P27D1 is shift solenoid five hydraulically stuck off in this GM transmission. The integrity routine commands small movements of rod five with opposite selector states. Unlike the valve-three and valve-four arrangement, the source explicitly says there is no redundant valve-and-rod path available to validate this result.
Why a flat position trace is insufficient
The listed motion criteria remain at or below 100 micrometres during the relevant cases. That can make the hydraulic path suspicious, but a position sensor stuck at a value can look similar. The controller therefore uses the valve-five current-profile check to separate the possibilities.
The source requires three failed profile results and transmission oil temperature of at least 40°C. These corroborating conditions are central to the diagnosis, not optional refinements after an assumed mechanical failure.
A complete verification record
Retain the executed integrity cases, rod-five response, oil temperature and current-profile outcomes. Lack of code return without those tests does not demonstrate a passed diagnosis. The routine uses small test movements rather than complete gear engagement. This summary explains the specific evidence combination, but the applicable transmission service procedure is required before intrusive testing or component replacement.
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 Performance/Stuck Off
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