Diagnostics
OnStar Vehicle Diagnostics will
perform a vehicle check every
month. It will check the engine,
transmission, antilock brakes, and
major vehicle systems. It also
checks the tire pressures, if the
vehicle is equipped with the Tire
Pressure Monitoring System. If a
diagnostics check is needed
between e-mails, push 
, and
an Advisor can run a check.
See also:
When to Inspect the Engine
Air Cleaner/Filter
Inspect the air cleaner/filter at the
scheduled maintenance intervals
and replace it at the first oil change
after each 80 000 km (50,000 mile)
interval. See Maintenance Schedule, for more inf ...
Compass
The vehicle may have a compass in
the Driver Information Center (DIC). ...
Battery Load Management
The vehicle has Electric Power Management (EPM) that estimates the battery's
temperature and state of charge. It then adjusts the voltage for best performance
and extended life of the battery. ...