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OBD-II Diagnostic port locations
Due to the fact that the GM OnStar system sends transmissions periodically to the vehicle we
suggest that the system should temporarily be disabled during the installation
and modification process.
If the OnStar system is not disabled during install or modification and the system should receive a
transmission in the middle of tune install or backup, the tool will be interrupted and the process will
have to be started over again.
To avoid this problem it is recommended that the OnStar system is disabled during tune install,
backup and modification.
To disable the OnStar system, please refer to your owner’s manual and locate the fuse(s) associated
with the OnStar. The OnStar system is disabled when the OnStar light is not lit.
On some vehicles it is necessary to remove more than one fuse; this will be indicated by the OnStar
light still lit after removal of the fuse from the engine compartment fuse panel.
Vehicles equipped with the GM OnStar system
Vehicles equipped with
the GM OnStar system
