Diagnostic article Generic OBD-II
P2829: Selector pilot stuck-off is distinguished from a selector spool fault
P2829 combines wrong-route rod movement with failed pilot-valve current-profile checks in the synchronizer recovery routine.
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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.
P2829 corresponds to the selector pilot valve hydraulically stuck off in this transmission. The integrity routine commands the selector toward hydraulic on, but the rod response matches the opposite routing state. The intended rod moves no more than 100 micrometres while a complementary rod moves more than 100 micrometres.
Routing evidence does not identify the pilot by itself
The controller then uses the pilot valve’s current-profile results to distinguish that valve from the downstream selector mechanism. Repeated profile failures support the pilot-valve classification. Cooler-out temperature must be at least 40°C, and the requested integrity routine must meet its operating conditions.
The continuation’s confirmation labels include a stuck-on wording under this stuck-off row. That source inconsistency is retained as a review issue; the article does not infer a different failure direction from the isolated label.
Preserve the completed sequence
Useful evidence includes the selector target, intended and complementary rod responses, temperature and current-profile history. A failed shift alone does not contain that comparison. The source describes controlled small movements and does not provide a universal procedure for executing them manually. Apply the actual transmission service information before attributing the fault to a replaceable pilot valve.
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 K 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