P0461: A fuel-level reading that barely changes while fuel is consumed

P0461 checks fuel-level sensor performance in the cited GM single-tank application. It looks for a primary level signal stuck within its normal range. That is different from an output that crosses an electrical high or low boundary.

Consumption supplies the comparison

The documented failure is sensed volume changing by less than three litres while engine fuel consumption exceeds 15.56 litres. The diagnostic is enabled while the engine operates and samples at 250-millisecond intervals, with Type B reporting.

Those quantities explain why an apparently plausible fuel gauge can still be suspect. The concern is its lack of movement over meaningful consumption, not whether the current displayed amount seems reasonable. A brief idle check cannot reproduce that accumulated comparison.

Evidence across time is more useful

Record the fuel-level trend and the controller's consumption information over the relevant period. Confirm the vehicle actually uses the single-tank architecture covered by this row. A second tank, transfer strategy or different sensor arrangement would require its own documented logic.

The code does not prove a float is physically stuck or identify an electrical component to replace. It establishes a mismatch between indicated change and consumed fuel. Use the applicable sensor and system procedure to resolve that mismatch, then verify that the performance monitor sees credible level movement. Do not deliberately run the tank empty to produce a test; the source describes a monitor, not that workshop method.

Source and applicability

This explanation is limited to the 2025 GM 25OBDG03A monitor on page 299. Its thresholds are calibration examples, not universal specifications. Confirm the vehicle, engine and controller procedure before applying them.