Diagnostic article Generic OBD-II
P2835: Rod-one intermittent code checks digital frequency, not just dropouts
P2835 evaluates rod-one signal frequency outside the documented range, with an explicit reference-supply limitation.
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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.
The P2835 implementation in this source is a frequency check on the rod-one position signal. It rejects a digital input below 1,500 Hz or above 2,500 Hz after the listed 150 ms interval. Although the generic title says intermittent, the documented criterion is more specific than “the connection sometimes disappears.”
A changing position is not the measured quantity
Signal frequency and reported rod position are different pieces of information. A position value that looks steady cannot prove the digital carrier is within range. Likewise, the presence of some pulses does not establish that their frequency is acceptable.
The table’s VREF1 enable entries are internally incompatible: above 5.5 V and below 4.5 V. The original rendering confirms the wording, so this article does not silently replace it with an assumed normal window. P0642/P0643 and P0882/P0883 are listed as inhibits.
Verification needs timing information
Preserve actual frequency and fault duration with supply-diagnostic status. A simple continuity observation cannot reproduce the frequency calculation. Confirm the correct calibration and reference-supply conditions in applicable service information before applying the limits to a vehicle. The DTC does not by itself prove a mechanically damaged fork or identify the component responsible for the signal timing.
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
Shift Fork A Position 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