Diagnostic article Generic OBD-II
P0874: system-pressure sensor zero-offset assessment
P0874 is described here as system-pressure-sensor drift outside its allowed window.
Read before applying this article
Documented application
2025 GM 25OBDG07A Part2 diagnostic monitor documentation; the application-matrix filename mismatch is unresolved, so no model or engine 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.
P0874 is described here as system-pressure-sensor drift outside its allowed window. The documented test is more specific than the catalog’s intermittent pressure-sensor C circuit label.
The raw reading is judged at expected zero
The controller evaluates the absolute raw system-pressure measurement when the system’s zero-pressure condition applies. The allowable drift window and definition of that condition are supplied by referenced attachment tables, so no fixed pressure limit is inferred from this page.
The enable list requires controller awake time above 20 milliseconds, acceptable application state, no code-clear event, and an electrical sensor diagnostic that indicates okay. These conditions separate offset assessment from a simple electrical high/low fault.
Different questions need different evidence
A normal electrical-range test does not prove the sensor’s zero offset is correct. Likewise, a nonzero reading while the hydraulic system is actively pressurized is not evidence of the zero-state error this monitor seeks.
For verification, preserve the raw reading and proof that the correct zero-pressure state was established. The page contains awkward sample-validity and clutch-versus-system wording, so this article does not reconstruct a complete service sequence from it. Use the applicable professional diagnostic to confirm a completed drift check; the code alone does not prove actual residual pressure or identify a failed hydraulic component.
Documentation and applicability
These details describe the monitor in GM’s 2025 25OBDG07A Part2 file. Its application-matrix filename does not match the download index, so model and engine applicability remain unresolved. Use the vehicle’s correct service information before applying these calibration details.
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
Transmission Fluid Pressure Sensor/Switch C Circuit Intermittent
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