P02B1: The cylinder 6 leakage monitor needs an eligible operating window

P02B1 names cylinder 6 injector leakage. The cited GM strategy is sensitive to operating eligibility: a code that does not reappear during idle has not necessarily passed the running assessment described in the document.

Why an idle observation is incomplete

The monitor requires engine speed above 1,520 rpm and below 6,000 rpm, together with relative air charge below 100 percent. It also excludes injector electrical failure and statistical inhibition. These are conditions for interpreting evidence, not instructions to conduct a road or loaded-engine test without the proper service procedure.

Within that window, the controller combines more than 100 cylinder 6 misfire counts with a minimum error in rail-pressure control. It allocates five seconds to the check and uses two-trip reporting. The inferred condition is an injection valve mechanically failing open.

What would demonstrate meaningful verification

Retain cylinder 6’s counter, rail-control status and the monitor’s eligibility or completion information. A cleared dashboard warning alone does not show that the same combination has been reevaluated successfully.

P02B1 shares this documented method with neighboring cylinder leakage codes, but its cylinder assignment remains specific. Do not infer physical cylinder location from the number alone. The code narrows the investigation without proving the failed component; confirmation requires the installed engine’s high-pressure fuel-system diagnostics and appropriate professional handling.

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 708.