See also:

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 vehic ...

Fluids
Proper fluid levels and approved fluids protect the vehicle’s systems and components. See Recommended Fluids and Lubricants on page 11‑12 for GM approved fluids. • Engine oil and windshield ...

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF in each shift lever position. ○ The ignition should turn to LOCK/OFF only when the shift lever is in P (Park ...