P082C: An excessive X-sensor duty cycle is separate from selector travel

P082C is the high-circuit code for gear-lever X position sensor 1. The GM monitor evaluates whether this channel's measured duty cycle exceeds its electrical range. A high percentage is not a calibrated claim about how far the driver has moved the lever.

The upper signal boundary and sample history

The table sets the failure threshold above ninety-five percent. Monitoring begins only after the controller has been awake for at least 0.05 second. The result requires ten failures in twelve samples on a 25-millisecond loop, with two-trip reporting.

That combination means a single peak during wakeup is not the same evidence as repeated high-duty samples after enablement. Preserve the raw sequence and wakeup state rather than relying only on a final screenshot of the displayed gear.

Use the correct X channel

Sensor 1 and the X axis are part of the code's identity. A normal Y-axis signal or a result from another sensor does not establish that this exact channel remained in range. Likewise, an average voltage reading cannot be treated as duty cycle without knowing the signal format.

The document does not provide the percentage-to-position map or prove that the transmission has engaged an unsafe or unintended range. It supports investigation of a high electrical signal on the specified selector channel. Component isolation and any selector replacement decision require the applicable circuit and calibration information.

Source and applicability

2025 GM 03B documented monitor only. Vehicle, engine and controller calibration applicability must be established separately; no model fitment is inferred from the file. GM PDF, physical page 608.