Diagnostic article Generic OBD-II
P2293: regulator-controlled rail pressure exceeds a speed-dependent ceiling
P2293 detects rail pressure above a calibrated engine-speed-dependent maximum while the pressure regulator governs control.
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Documented application
Documented 2025 GM diagnostic parameter monitor in 25OBDG04B.pdf; model, engine and calibration applicability require vehicle-specific confirmation.
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.
P2293 is a regulator 2 performance code in the reviewed GM implementation. The monitor checks whether rail pressure exceeds the maximum allowed while the pressure regulator is governing the system. It is not simply a comparison with the requested pressure, nor does it use one ceiling at every engine speed.
The ceiling is mapped
The supporting normal map ranges from 68 to 268 MPa and varies with engine speed. It allows 268 MPa across its central speed region but lowers the ceiling toward the map's high-speed end. A separate extended-area map also applies when that calibration area is enabled.
A pressure value that appears acceptable at one engine speed may therefore exceed the limit elsewhere. Comparing a freeze-frame pressure with the map's largest number alone can miss the actual reason for qualification.
Conditions and confirmation
Relay voltage must be at least 11 volts and pressure-regulator control must be active. The diagnostic qualifies through 121 failing samples within 242, or 121 continuous failures, at 6.25 milliseconds per sample. Reporting is Type A over one trip.
Verification should establish engine speed, selected control mode and the applicable normal or extended ceiling alongside measured rail pressure. An electrical pass on the solenoid does not independently establish hydraulic control. The source does not identify the cause of excessive pressure or a replacement part. High-pressure fuel-system testing requires the vehicle's professional service procedure; these 2025 GM limits must not be applied to an unidentified engine or calibration.
Source: GM monitor, PDF page 812; GM monitor, PDF page 1765; GM monitor, PDF page 1885.
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
Fuel Pressure Regulator B Performance
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