P2180: Bank 2 rich off-idle adaptation and the limits of a simple trim screenshot

P2180 describes system too rich off idle on bank 2. The documented GM monitor uses the multiplicative part of bank 2 long-term fuel trim, with a lower failure boundary of 0.73 in gasoline-mode operation.

A low learned factor must meet stability conditions

The row lists a 0.2-second evaluation period, but its continuation requires active adaptation and qualified integrator behavior. Speed, load and changes in correction contribute to the stability assessment. That short period is not the total time needed for the system to learn a meaningful correction.

The continuation also refers to a bank 1 additive-term value within the bank 2 eligibility logic. The source does not explain that cross-bank reference here. This article therefore does not reduce the full conditions to an assumed bank-2-only workshop test.

Use the code as adaptation evidence

Keep multiplicative, additive and short-term data separate. A scanner that converts factors to percentages may display a different numerical representation of the same correction, and the code's 0.73 boundary should not be compared to an unidentified parameter.

The monitor establishes that a qualified learned correction crossed its lower limit; it does not determine which fuel, air or sensing component caused that correction. Preserve the bank 2 value and monitor eligibility with the fault record. A successful verification requires valid adaptation and test completion. Clearing learned values or observing one normal snapshot after changing load cannot independently prove that the rich-condition cause has been resolved.

Source and scope

2025 GM 25OBDG07A Part 2 monitor tables only; model, engine and transmission applicability are not established by the unresolved application-matrix filename join. These are documented monitor criteria, not a universal repair procedure. GM PDF, physical page 196 · GM PDF, physical page 197.