Diagnostic article Generic OBD-II
P27D7: Valve-five low-circuit classification must be separated from stuck-off behavior
P27D7 is a driver electrical check on synchronizer valve five, with supply and switching-state requirements.
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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.
P27D7 is the circuit-low diagnostic for synchronizer actuation valve five in this controller. The source uses the driver’s short-to-ground classification for its monitored output node. It does not infer this electrical condition merely because rod five failed to move.
Operating state affects interpretation
The row describes evaluation during solenoid actuation with internal switching-time conditions. The DTC interval is at least 150 ms. An isolated voltage value, without knowing how the driver was commanded, loses the context needed to compare it with the monitor.
Battery voltage must be above 8.75 V and below 18 V. The system must be outside safe state, the engine not cranking and the key not in stop. Supply faults P0882 and P0883 inhibit the routine.
Build separate electrical and hydraulic evidence
Retain valve-five driver status, command and controller voltage before deciding whether a hydraulic symptom shares the same cause. The separate stuck-off monitor uses rod motion and current-profile evidence, which this low-circuit code does not replace. Vehicle-specific service documentation must identify the actual circuit and safe measurement procedure. The source does not isolate a coil, connection, harness or output-stage defect solely from the DTC.
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 Control Circuit Low
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