P2B96: Global injection-pulse monitoring detects missing opening signatures

P2B96 is the total-engine missing-injection-pulse performance monitor in the reviewed GM source. It can be triggered by opening-feedback evidence from any pulse on any cylinder; a global code does not mean that every cylinder failed.

The controller infers injector movement

Pintle or armature motion changes the magnetic flux in an injector coil. The ECM measures voltage feedback across the enable and command wires and converts it into opening-magnitude metrics. An absent detectable opening or a failed calibrated magnitude comparison provides evidence that a commanded pulse was not delivered as expected.

The source references several magnitude and delta criteria, with supporting tables indexed by measured rail pressure. Their internal numbers are not universal external injector-voltage specifications and should not be used for improvised probing.

Valid feedback is required

The small-pulse general diagnostic enable and fuel-pulse voltage-feedback-data-ready states must both be true. The row lists continuous evaluation at a 100-millisecond frequency and a 100-count/sample entry. It does not provide a complete standalone service procedure for reconstructing that internal decision.

A normal injection command without valid opening feedback does not establish a pass. Preserve cylinder-specific companion codes and available feedback details to narrow the global finding; this code alone cannot choose the cylinder or component requiring repair.

Verification should demonstrate accepted opening signatures through an enabled completed evaluation. Unlike the separately documented P2B95 startup test, this row is a general continuous monitor. The source lists Type B, two-trip behavior without a mandatory injector replacement.

Source and applicability

This description is limited to the stated monitor; vehicle, engine and calibration matching remain necessary. GM diagnostic table, PDF page 684. GM diagnostic table, PDF page 1022. GM diagnostic table, PDF page 1023. GM diagnostic table, PDF page 1024.