Diagnostic article Generic OBD-II
P268A: injector calibration data fails its programming-integrity check
The GM P268A example checks injector-adjustment data integrity during pre-drive, rather than measuring injector fuel delivery.
Read before applying this article
Documented application
GM 2015 15OBDG09 LML/LGH-common injector-calibration 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.
P268A identifies missing or invalid injector-calibration programming in this GM implementation. The table describes an integrity check of the injector adjustment code words stored in the ECM. It does not diagnose injector spray quality, fuel leakage or rail pressure by performing that check.
Programming data and physical injector behavior are different
The published criterion is that the adjustment-code checksum is not correct. A checksum verifies the integrity of the stored data; it is not a direct measurement of how much fuel an injector delivers. A repair explanation should therefore establish the state of the required calibration records before interpreting P268A as a mechanical injector failure.
The source identifies a pre-drive evaluation once per driving cycle, with a one-second failure condition. An extended running test does not necessarily repeat the same startup-stage check in the way a continuously active sensor monitor would.
Preserve the coding history
Record any injector replacement or controller-programming work, the installed components and the applicable calibration information. Those records can guide the authorized service procedure, but P268A alone does not establish which prior action caused the data problem.
The next page describes separate cylinder-specific disagreements between ECM and glow-plug-module adjustment values. That comparison is distinct from this checksum-based programming-integrity fault. Use the exact engine's procedure to verify and correct the required data, then confirm a valid pre-drive evaluation. Clearing fault memory or replacing an injector without addressing its required calibration record does not demonstrate completion.
Source and applicability
GM 2015 15OBDG09 LML/LGH-common injector-calibration monitor. Only the cited monitor and calibration are described; per-code vehicle and engine applicability has not been established.
15OBDG09 Engine Diagnostics, physical PDF pages 233, 234.
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
Fuel Injector Calibration Not Learned/Programmed
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