P02F5: Cylinder 8 injector performance uses event-based signal plausibility

P02F5 is the cylinder 8 injector circuit range/performance entry. Its cited GM monitor evaluates the internal signal buffer associated with controlled valve operation. This is a different diagnostic question from whether the injector physically leaks or supplies the correct fuel quantity.

Event counting is part of the diagnosis

The table specifies a 20-event evaluation and two-trip reporting. The relevant events are part of the monitor’s signal evaluation, so the number cannot be treated as a simple elapsed-time requirement.

Two buffer positions are checked: one at the beginning of the evaluation window and one at the end. The conditions are alternatives, meaning the same code does not identify which boundary was responsible without additional diagnostic information. The values are ADC counts rather than external circuit-test voltages.

Preserve the level of evidence

Use the manufacturer’s full fault detail where available to identify the failing signal-evaluation path. A generic scan label may expose only the cylinder association while hiding this internal monitor logic. Ignition must be on, and other enable and inhibit conditions can determine whether the check runs.

The source summary does not establish connector location or prove which component failed. Its cylinder 8 association needs the applicable engine mapping, and any electrical verification should follow that service procedure. Replacing an injector solely because the short title says “performance” would skip the actual buffer-plausibility evidence described here.

Source and applicability

This explanation covers the cited GM monitor, not every vehicle carrying this code. The application-matrix filename does not resolve cleanly to this file, so no model or engine fitment is assigned. GM diagnostic table, PDF page 609.