P0273: injector 5 driver has an off-state short-to-ground pattern

P0273 identifies the low-side electrical short-to-ground monitor for injector 5. The ECM sees low voltage during the driver's off state. The GM threshold description associates that pattern with low-side-to-controller-ground impedance of 0.5 Ω or less.

Confirm the channel and state

The cylinder number identifies the monitored injector circuit, not its physical position on every engine. Use the actual engine's numbering and wiring information. Also retain whether the driver was off: low feedback during commanded conduction has a different meaning from the unexpected off-state result recorded here.

The test is calibration-enabled, with key on, battery voltage above 11 V, no cranking and at least one second of engine operation. An injection request and the required output-enable status must be present. It uses four failures out of eight 100-millisecond samples and Type A, one-trip reporting.

What this result does not measure

P0273 does not assess injector-5 flow calibration, spray quality or fuel-start angle. If performance codes also exist, keep the electrical result in context before interpreting their separate tests.

Verification needs acceptable off-state feedback throughout an eligible evaluation, not only a currently smooth engine. Circuit isolation and driver testing require the vehicle-specific professional procedure. The table does not identify where the ground path is or justify opening high-pressure fuel lines to investigate this electrical fault.

Source and applicability

GM 04B, PDF page 1133. This explanation covers the documented 2025 monitor. Confirm the vehicle's module, engine and calibration before applying these criteria; the document's vehicle list does not establish this code's applicability to every listed model.