See also:

How to Inspect the Engine Air Cleaner/Filter
To inspect the air cleaner/filter, remove the filter from the vehicle and lightly shake the filter to release loose dust and dirt. If the filter remains covered with dirt, a new filter is required ...

When the System Does Not Seem to Work Properly
The following messages may be displayed on the DIC: SERVICE PARK ASSIST: If this message occurs, take the vehicle to your dealer to repair the system. PARK ASST BLOCKED SEE OWNERS MANUAL: This messa ...

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 v ...