P02DB: Cylinder 8 upper offset learning requires checking retained saturation states

P02DB is the maximum offset-learning entry for cylinder 8. The cited GM monitor assesses whether a small-quantity energizing-time correction exceeds its allowed upper boundary. Its evidence is stored learning behavior, rather than a one-time rail-pressure reading.

One saturated pressure region can retain the finding

Each new correction generated by small-quantity learning is compared with a calibrated maximum. The resulting saturation status is stored by rail-pressure level in nonvolatile memory. The strategy can report the authority limit when at least one element is true, and describes the condition as unset when all elements are false.

A live correction at one pressure therefore cannot stand in for the whole map. Record which learning region was limited and whether the system has subsequently had a valid opportunity to update that region.

Be precise about the upper boundary

The table's title, greater-than comparison and maximum-status wording agree on the upper-limit meaning. A later sentence nevertheless calls it minimum authority. That label inconsistency is disclosed here; it is not used to reverse the meaning or guess a threshold.

The document identifies a calibration parameter rather than publishing a universal microsecond limit. It also requires enabled learning management and authority diagnosis. Verification needs completed learning under those conditions, not simply an erased fault display. The source does not identify an injector replacement or provide a safe stand-alone procedure for testing high-pressure fuel hardware.

Source and applicability

2025 GM 04A documented monitor only. Vehicle, engine and controller calibration applicability must be established separately; no model fitment is inferred from the file. GM PDF, physical page 929; GM PDF, physical page 930.