P2B02: Cylinder 3 injection pulses fail the opening-feedback check

P2B02 indicates that the controller did not detect the expected opening behavior for a cylinder 3 injection pulse in the reviewed GM monitor. The diagnosis is derived from injector coil voltage-flux feedback associated with pintle or armature motion.

What an opening-magnitude result means

The ECM measures feedback between enable and command wires and converts it into an injector opening-magnitude metric. The source describes failure when opening cannot be detected or when the measured metric fails its calibrated missing-pulse limit.

The supporting table uses a measured-fuel-rail-pressure axis for that metric. Its internal opening-magnitude numbers should not be turned into a universal external injector-voltage specification. A compatible service procedure is needed to interpret the controller's data correctly.

Sampling is tied to cylinder events

Small-pulse general diagnosis must be enabled, and fuel-pulse feedback data must be ready. The listed evaluation requires 50–100 samples taken at cylinder events, rather than a fixed time-only observation.

Consequently, correct command timing alone does not prove detected opening, and an engine-running interval with unavailable feedback does not demonstrate a pass. Preserve both command and feedback-readiness information before choosing a repair.

Confirm the engine's actual cylinder 3 identity; this source does not locate it physically. Verification requires acceptable opening feedback through an eligible completed evaluation. The Type B, two-trip classification does not identify a fuel contaminant, establish injector flow quantity or mandate replacing cylinder 3's injector.

Source and applicability

This description is limited to the stated monitor; vehicle, engine and calibration matching remain necessary. GM diagnostic table, PDF page 670. GM diagnostic table, PDF page 1024.