P2C08: Intake sensor A circuit high is checked after the output is switched off

P2C08 is the high electrical classification associated with intake profile-position sensor A. GM explicitly checks the driver-off state and describes a short toward power. Voltage that is expected during an on command cannot be judged by the same rule as voltage remaining after an off command.

Observe the commanded-off circuit

The table’s voltage limits are controller-specific and represent impedance below 0.5 Ω toward controller power. This describes the classification basis; it does not identify a universal voltage at an unnamed sensor connector.

The neighboring low-circuit monitor, P2C07, requires the driver on. That opposite command condition is why a single static reading cannot conclusively evaluate both fault types. The transition and the command state need to be preserved.

Confirm repeated eligible evidence

The diagnostic requires supply above 11 V and ignition in crank or run. Four failed reports out of five samples establish the row’s result, with one-trip reporting specified separately. An isolated power-up transient is not automatically the same event.

Useful verification records the intake A channel, off command, electrical response and supply qualification. A valid Hall position at another time does not locate or disprove the unwanted power path described here. The source does not decide whether a sensor-associated circuit, harness or controller is responsible, and it does not justify replacing a camshaft mechanism from the high-circuit label alone.

Source and applicability

2025 GM 25OBDG03B documented monitor only. Vehicle, engine and calibration applicability must be confirmed from the matching service information; no model fitment is inferred. These criteria explain controller logic, not a complete repair procedure. 25OBDG03B, PDF page 899. 25OBDG03B, PDF page 900.