Diagnostic article Generic OBD-II
P2746: Clutch-two speed plausibility needs pressure and slip context
P2746 compares clutch-two speed with independent references while excluding conditions that could create real clutch slip.
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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.
P2746 is used here for clutch-two speed-sensor consistency. One branch compares that sensor with engine speed while clutch two is fully closed. An absolute difference of at least 150 rpm lasting 1,100 ms is the listed failure criterion for that branch.
Why pressure control matters
The comparison is enabled only with no electrical speed-sensor fault, no microslip function and satisfactory even-clutch pressure control. The source also limits the difference between pressure request and target. These prerequisites matter because genuine clutch slip would otherwise resemble a sensor disagreement.
A second branch compares the sensor with speed derived from the output and engaged gear. It requires agreement between gear-position evidence and the logical gear, plus output-speed consistency with wheel-speed information. This is a cross-check among independent signals, not a conclusion drawn from one rpm display.
Preserve the qualifying conditions
Record engine, clutch-two and output-speed information with clutch state and pressure-control status. A disagreement during an intentional slip phase is not the same evidence as the closed-clutch branch. The source explains how the controller rejects inconsistent information; it does not prove that a speed sensor is defective without verifying the conditions that exclude actual mechanical slip.
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
Intermediate Shaft Speed Sensor B Circuit Range/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