See also:

Shifting Out of Park (P)
Your vehicle has an automatic transmission shift lock control system. You have to fully apply the regular brakes first and then press the shift lever button before you can shift from PARK (P) when ...

When to Add Engine Oil
If the oil is below the L mark for the L6 engine or the cross-hatched area at the tip of the dipstick for the V8 engine, you will need to add at least one quart/liter of oil. But you must use the ...

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 ...