P2834: Rod-one circuit high can be a missing-pulse or duty-cycle fault

For P2834, GM’s rod-one position monitor detects either a pulse-free high input above 3.5 V or duty cycle above 92%. The high label therefore describes electrical signal quality, not a mechanically high fork position or proof that the rod overtravelled.

Keep both failure paths visible

A digital input can appear high at an instant while still producing normal pulses. The missing-pulse branch needs the absence of transitions as well as the high level. Conversely, the excessive-duty branch can fail while pulses still exist. The table lists at least 150 ms confirmation.

The VREF1 enable rows in the original PDF show mutually incompatible above-5.5-V and below-4.5-V conditions. This article flags that conflict and does not invent corrected limits. Reference-supply and controller-voltage inhibit codes are listed separately.

What to verify

Record pulse presence and duty cycle with the reference-supply diagnostic state. A position display or average voltage alone cannot distinguish the two branches. Resolve the calibration’s actual supply prerequisites through applicable service information before declaring a pass. The source provides a fault classification but does not isolate the sensor, wiring or controller as the defective part.

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 912.