P0792: clutch-1 speed checked against independent references

P0792 is implemented here as clutch-1 speed-sensor consistency monitoring. The generic intermediate-shaft-sensor A label should be mapped to this transmission’s actual channel before interpreting the result.

Three comparisons provide different evidence

With clutch 1 fully closed, microslip inactive, and pressure control acceptable, measured clutch speed should match engine speed. A difference of at least 150 rpm qualifies for 1,100 milliseconds in that branch.

Another branch compares clutch speed with speed calculated from the output shaft and engaged ratio. It requires output-speed consistency with driven-wheel information and agreement between the logical gear and rod-position sensors. Its confirmation interval is 200 milliseconds.

The continuation describes a shift-time comparison: rod movement and position indicate successful engagement while the calculated synchronizer speed difference remains above 200 rpm. That branch uses 50 milliseconds.

Identify the reference before replacing the sensor

A clutch-to-engine mismatch during intentional microslip is not the first branch’s test. A ratio-based mismatch without confirmed gear position is not the second branch’s test. These prerequisites help prevent ordinary operating differences from being treated as sensor errors.

Verification should show the relevant consistency branch completing with trustworthy reference inputs. The code alone does not establish that clutch friction parts are slipping or that the speed sensor must be replaced.

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.

GM diagnostic table, PDF page 982; GM diagnostic table, PDF page 983.