Diagnostic article Generic OBD-II
P219D: interpret cylinder-two imbalance against the correct bank baseline
P219D in the GM monitor compares cylinder two with its bank; a bank fuel-trim value alone cannot establish the cylinder diagnosis.
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Documented application
GM 2020 20OBDG07 shared cylinder air-fuel imbalance monitor. Only the cited monitor and calibration are described; per-code vehicle and engine applicability has not been established.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P219D points to cylinder two in the air-fuel imbalance family. The cited GM monitor evaluates how that cylinder differs from its bank's average behavior. A scan showing only a bank fuel-trim number therefore does not reproduce the cylinder-specific evidence behind this fault.
Resolve direction before discussing a repair
P219D is included in both the lean and rich monitor paths. Their normalized limits differ, but the code remains the same. Treating every P219D as a lean fuel-delivery problem would ignore the documented rich-side possibility.
Ask for the cylinder-specific findings, the bank comparison and the operating point recorded when the test failed. The numerical limits in this table belong to the controller's modeled comparison; they should not be converted into a universal injector flow tolerance or a permissible fuel-pressure error.
A valid roughness signal is a prerequisite
The monitor depends on plausible segment timing and learned trigger-wheel correction. It also excludes active rough-road detection and requires normal synchronized engine operation. Those requirements help distinguish an eligible combustion-related comparison from a period in which the input used for that comparison is unreliable.
The table does not specify cylinder-two physical location for every engine, and it does not order replacement of any component. Confirm the actual engine's numbering and service procedure before identifying parts. After an evidence-based correction, verify that the comparison has run in its calibrated operating region. Simply clearing the code, idling briefly or changing a bank-wide adaptation value does not demonstrate that the cylinder-two imbalance was resolved.
Source and applicability
GM 2020 20OBDG07 shared cylinder air-fuel imbalance monitor. Only the cited monitor and calibration are described; per-code vehicle and engine applicability has not been established.
20OBDG07 Diagnostics, physical PDF pages 129, 130, 131, 132, 133, 134.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Cylinder 2 Air-Fuel Ratio Imbalance
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT