P233C: fuel metering valve 2 low-side short to power

P233C identifies a short-to-power condition in the low-side circuit of fuel metering unit valve 2. The generic code name uses fuel pressure regulator C; the component wording here comes from the specific GM monitor.

On-state electrical feedback

The controller expects the low-side driver to behave appropriately when switched on. A high voltage across that driver during the on-state is classified as a power short. The table associates the classification with an impedance below 0.5 ohm between the valve's low-side pin and controller power. That specification is not a rail-pressure value or a live-circuit resistance-test instruction.

Monitoring requires relay voltage above 11 V, no engine cranking and run/crank active. Sampling is listed at 100 ms, with Type A, one-trip reporting. The source leaves the failed-sample counts blank, so it does not support an exact detection delay.

Making the result actionable

Preserve both the driver command and fault status. A high reading taken while the driver is off answers a different question from the on-state comparison used here. Use the correct service diagram to separate supply and low-side circuits before diagnosing their connection to power. Confirmation is a completed electrical test without the short-to-power state, not simply acceptable fuel pressure. Fuel-system disassembly is outside the evidence supplied by this table and should follow professional service procedures.

Source and application limits

This explanation covers the cited 2025 GM monitor. Confirm the vehicle and calibration in its service information before applying these limits; inclusion in this file does not establish model compatibility. GM diagnostic parameters, PDF page 818.