P2841: Rod-four plausibility depends on learned position and even-side speed checks

P2841 is the consistency code for rod-four position in this transmission. During engagement, speed evidence may show that a gear is engaged while the rod reading stays more than 1,100 micrometres from its learned engaged position. The controller requires sufficient force request and no electrical position-sensor fault before interpreting that mismatch.

Static drift is a separate branch

When no outside rod force is present, the controller checks learned position tolerance bands. A value outside them becomes suspicious. It then corroborates the speed references using even-clutch versus engine speed and output speed versus driven-wheel information, with a 500 ms position-fault interval.

One static-boundary line refers to rod-three measurement within the rod-four section. That apparent cross-channel reference remains a review issue; this article does not invent the intended correction or apply that particular boundary.

Preserve which comparison failed

Keep learned positions, actual gear state, force commands and supporting speed data together. A single position display does not indicate whether the dynamic or static branch was evaluated. Use the actual transmission’s service documentation to resolve the cross-channel wording and complete component isolation. The code is not a universal instruction to replace the fork-D sensor.

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.

GM physical PDF page 968, GM physical PDF page 969, GM physical PDF page 970.