P02EF: Cylinder 2 injector feedback can be present but implausible

The cited P02EF monitor evaluates cylinder 2 injector voltage feedback for rationality. It converts electrical feedback into opening magnitude and closing time, then compares those derived values with calibration limits. It also detects cases where the corresponding event cannot be recognized at all.

Missing event versus wrong event size

A failure may mean no opening magnitude was detected, or that a detected opening is too small or too large. Closing evaluation similarly distinguishes absent timing from timing outside the permitted range. These alternatives matter when choosing what evidence to collect: a single label of “injector performance” conceals several possible feedback failures.

The controller only makes this judgment when pulse width is long enough for full pintle travel and stabilized coil behavior. Valid feedback data and the general small-pulse diagnostic enable are also required. An ineligible short injection event should not be used as proof of poor opening response.

Confirm the applicable calibration

The actual minimum/maximum opening and closing limits are in supporting tables, not universal values on this page. Sampling follows cylinder events, and the source lists Type B, two-trip reporting.

Compare eligible cylinder 2 feedback with the correct limits using the vehicle-specific procedure. Do not equate an implausible derived signal with proven injector-flow imbalance. After diagnosis, verify that valid, sufficiently long injection events produce a completed passing rationality monitor. High-pressure injection work and driver measurements require approved professional methods.

Source and applicability

This explanation is limited to the 2025 GM 25OBDG03A monitor on page 237, page 238. Its thresholds are calibration examples, not universal specifications. Confirm the vehicle, engine and controller procedure before applying them.