P21E7: The cylinder 6 injector B high-circuit check evaluates current under command

P21E7 is the generic cylinder 6 injector B circuit-high diagnosis. The GM injector-6 entry describes a short-to-supply electrical category and checks output current while the power stage is active. That combination defines the monitor more precisely than a broad “injector problem” label.

Three eligible events matter more than a static reading

The listed boundary is current above 3.8 A. The row specifies three events, engine speed of at least 80 rpm, battery voltage above 10.9 V and below 25.5 V, plus inhibition conditions referenced elsewhere.

An inactive output that later draws no current does not recreate the failed event. Likewise, a single external resistance observation does not directly measure the active-stage current criterion recorded by this monitor.

Keep neighboring fault classes distinct

The channel's open-load and low-circuit diagnoses use voltage with the power stage inactive. Their evidence is different from the energized-current observation associated with P21E7, even if all three point toward electrical investigation.

Confirm the actual engine's injector B arrangement before selecting a circuit or component. The source does not establish a connector location, a universal wiring topology or whether the injector load rather than wiring or the internal driver caused the result. It also does not assess fuel quantity or spray. Use the applicable circuit procedure to isolate the cause and judge recovery through eligible monitor completion, without turning the current threshold into a direct-power test instruction.

Source and scope

2025 GM 25OBDG07A Part 2 monitor tables only; model, engine and transmission applicability are not established by the unresolved application-matrix filename join. These are documented monitor criteria, not a universal repair procedure. GM PDF, physical page 557 · GM PDF, physical page 558.