P2833: Rod-one circuit low includes missing pulses or an undersized duty cycle

P2833 identifies an electrical-low fault on rod-one position feedback. The source describes two forms of evidence: no detected pulses with the pin below 2 V, or a duty cycle below 8%. A low instantaneous level during a valid pulse is not equivalent to either complete failure pattern.

Pulse quality is separate from rod position

The confirmation interval is at least 150 ms. This monitor assesses whether the digital signal is usable, not whether the mechanical rod is at a low position. A scan tool’s converted position value can hide the waveform condition behind the fault.

The original table prints incompatible VREF1 enable limits, above 5.5 V and below 4.5 V. Those numbers are not silently reversed here; exact reference-supply eligibility requires service-document confirmation. The listed inhibit codes include P0642/P0643 and P0882/P0883.

Verification focus

Preserve pulse presence, pin state and duty cycle together with reference-supply status. An isolated average voltage does not establish which branch failed. Use the actual transmission’s circuit specifications to resolve the enable conflict and signal test method. This code does not prove a damaged fork or identify a particular electrical component as the necessary replacement.

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.