P0276: injector 6 voltage low while the driver is off

The cited P0276 strategy checks injector 6's low-side control circuit for voltage that stays too low during the off state. GM describes this as a short-to-ground diagnosis. It is an electrical control fault, not a cylinder fuel-balance result.

Why the off phase matters

A low reading has diagnostic meaning here because the driver is supposed to be off. The table characterizes a short using impedance of 0.5 ohm or less between the low-side pin and controller ground. That specification describes the failure model; it should not be treated as a generic resistance test to perform on a powered circuit.

The monitoring filter needs four failures among eight samples at 100 ms per sample. An isolated transient and a sustained off-state low therefore do not represent the same evidence.

Reproducing the monitor

Battery voltage must exceed 11 V, the engine must have run for at least one second, cranking must have ended and software must request an injection pulse. A no-start cranking check is outside this documented run condition.

Diagnostic verification should retain cylinder identity and compare commanded operation with the circuit response using the correct service procedure. Do not interpret this code as proof of a clogged injector: the table measures the electrical return path, not spray quality or delivered fuel volume.

Source and applicability

2025 GM 25OBDG04B diagnostic parameter tables; the cited monitor only. Vehicle, engine and calibration applicability must be confirmed separately. These tables describe detection logic, not a complete repair procedure or a component replacement verdict. gm-2025-04b, PDF page 1135.